UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

_________________________________

Schedule 14A

_________________________________

Proxy Statement Pursuant to Section 14(a) of the
Securities Exchange Act of 1934

Check the appropriate box:

EnLink Midstream, LLC
(Name of Registrant as Specified In Its Charter)

N/A

________________________________________________________________

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

MERGER PROPOSED — YOUR VOTE IS VERY IMPORTANT

Dear Unitholder of EnLink Midstream, LLC:

On November 24, 2024, EnLink Midstream, LLC (“EnLink”) and ONEOK, Inc. (“ONEOK”) entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Elk Merger Sub I, L.L.C., a direct, wholly-owned subsidiary of ONEOK (“Merger Sub I”), Elk Merger Sub II, L.L.C., a direct, wholly-owned subsidiary of ONEOK (“Merger Sub II”), and EnLink Midstream Manager, LLC, the managing member of EnLink (the “Manager”), pursuant to which (i) Merger Sub I will merge with and into EnLink (the “First Merger”), with EnLink as the surviving company and (ii) promptly following the First Merger, but in any event on the same day as the First Merger and as part of the same overall transaction as the First Merger, at the effective time of the Second Merger (as defined below), EnLink, as the surviving entity in the First Merger, will merge with and into Merger Sub II (the “Second Merger” and, together with the First Merger, the “Mergers”), with Merger Sub II surviving the Second Merger as a direct, wholly-owned subsidiary of ONEOK.

In the Mergers, the holders of common units representing limited liability company interests in EnLink (each such common unit, an “EnLink Unit,” and each such holder, an “EnLink unitholder”) will receive, for each EnLink Unit that they own as of immediately prior to the effective time of the First Merger (the “First Merger Effective Time”), 0.1412 shares of common stock of ONEOK, par value $0.01 per share (“ONEOK Common Stock”; such consideration, the “Merger Consideration” and such ratio, the “Exchange Ratio”). As of the effective time of the Mergers, the limited liability company interests in the Manager, and any EnLink Units that are owned immediately prior to the First Merger Effective Time by the Manager, ONEOK, Merger Sub I or Merger Sub II, will remain unchanged and outstanding until the effective time of the Second Merger and the Manager, as the holder of such managing member interests, will continue as the sole manager of EnLink. Prior to the First Merger Effective Time, each Series B Preferred Unit of EnLink Midstream Partners, LP (“EnLink Partners”) will be redeemed for cash or converted into EnLink Units pursuant to the terms of the EnLink Partners partnership agreement.

EnLink equity awards that are outstanding immediately prior to the First Merger Effective Time will be subject to the following treatment at the First Merger Effective Time:

•        each award of restricted incentive units of EnLink (each, an “EnLink RIU” and such award, an “EnLink RIU Award”), whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock equal to the number of EnLink Units subject to such EnLink RIU Award immediately prior to the First Merger Effective Time multiplied by the Exchange Ratio, rounded up or down to the nearest whole share of ONEOK Common Stock and otherwise subject to the same terms and conditions (including as to vesting and forfeiture) as were applicable to such EnLink RIU Award immediately prior to the First Merger Effective Time; and

•        each award of performance units of EnLink (each, an “EnLink PU” and such award, an “EnLink PU Award”), whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock with respect to each tranche of the EnLink PU Award as identified in the applicable award agreement (an “EnLink PU Tranche”) equal to the number of EnLink Units subject to such EnLink PU Tranche immediately prior to the First Merger Effective Time (determined as set forth below and, for those individuals who experienced a “Qualifying Termination” or “Retirement” (as such terms are defined in the applicable award agreement) prior to the transactions contemplated by the Purchase Agreement, dated as of August 28, 2024, by and among ONEOK, GIP III Stetson I, L.P., GIP III Stetson II, L.P. and Manager, acting solely in its individual capacity and not in its capacity as managing member of EnLink, taking into account any applicable proration provisions) multiplied

Special Meeting, has irrevocably agreed to vote in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal. Virtual attendance at the EnLink Special Meeting will constitute presence in person for the purpose of determining the presence of a quorum for the transaction of business at the EnLink Special Meeting.

The EnLink Special Meeting will be held virtually on January 30, 2025, at 10:00 a.m., Central Time. EnLink unitholders of record as of December 23, 2024 are entitled to vote at the EnLink Special Meeting. The EnLink Conflicts Committee and the EnLink Board have each unanimously approved the Merger Agreement and recommend that EnLink unitholders vote “FOR” the Merger Proposal. The EnLink Board unanimously recommends that EnLink unitholders vote “FOR” the Non-Binding Advisory Compensation Proposal.

If the Mergers are completed, at the First Merger Effective Time, each EnLink Unit issued and outstanding as of immediately prior to the First Merger Effective Time (except for any EnLink Units that are owned immediately prior to the First Merger Effective Time by EnLink as treasury units, if any, or by the Manager, ONEOK, Merger Sub I, or Merger Sub II) will convert automatically into the right to receive 0.1412 shares of ONEOK Common Stock, with cash paid in lieu of the issuance of fractional shares, if any. Although the number of shares of ONEOK Common Stock that EnLink unitholders will receive in exchange for their EnLink Units is fixed (subject to adjustments in accordance with the terms of the Merger Agreement), the market value of the Merger Consideration will fluctuate with the market price of ONEOK Common Stock and will not be known at the time EnLink unitholders vote to approve the Merger Agreement and the Mergers contemplated thereby. Based on the closing price of ONEOK Common Stock on the NYSE on November 22, 2024, the last trading day before the public announcement of the parties entering into the Merger Agreement, the Exchange Ratio represented approximately $16.53 in value for each EnLink Unit. Based on the closing price of ONEOK Common Stock on the NYSE on December 30, 2024, the last practicable trading day before the date of the accompanying proxy statement/prospectus, the Exchange Ratio represented approximately $14.23 in value for each EnLink Unit. Based on the estimated number of shares of ONEOK Common Stock and estimated number of EnLink Units, as well as the outstanding equity awards of the parties, that will be outstanding immediately prior to the consummation of the Mergers, we estimate that, upon consummation of the Mergers, current ONEOK shareholders will hold approximately 94.1%, and current EnLink unitholders will hold approximately 5.9%, of the issued and outstanding shares of ONEOK Common Stock (in each case based on fully diluted shares or units, as applicable, outstanding of each company). We urge you to obtain current market quotations for ONEOK Common Stock (trading symbol “OKE”) and EnLink Units (trading symbol “ENLC”).

The obligations of ONEOK and EnLink to complete the Mergers are subject to the satisfaction or waiver of a number of conditions set forth in the Merger Agreement, a copy of which is attached as Annex A to the accompanying proxy statement/prospectus. The accompanying proxy statement/prospectus describes the EnLink Special Meeting and the proposals to be considered thereat, the Mergers and the documents and agreements related to the Mergers. It also contains or references information about ONEOK and EnLink and certain related agreements and matters. Please carefully read the entire accompanying proxy statement/prospectus, including “Risk Factors” beginning on page 13, for a discussion of the risks relating to the proposed Mergers. You also can obtain information about ONEOK and EnLink from documents that each has filed with the U.S. Securities and Exchange Commission. Please see the section entitled “Where You Can Find More Information” beginning on page 115 of the accompanying proxy statement/prospectus for how you may obtain such information.

Neither the U.S. Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities to be issued in connection with the Mergers described in the accompanying proxy statement/prospectus or determined that the accompanying proxy statement/prospectus is accurate or complete. Any representation to the contrary is a criminal offense.

The accompanying proxy statement/prospectus is dated December 30, 2024 and is first being mailed to EnLink unitholders on or about December 31, 2024.

NOTICE OF SPECIAL MEETING OF UNITHOLDERS
OF
Enlink midstream, llc
TO BE HELD ON JANUARY 30, 2025

Dear Unitholder of EnLink Midstream, LLC:

On January 30, 2025, EnLink Midstream, LLC (“EnLink”) will hold a special meeting of unitholders (the “EnLink Special Meeting”) virtually at www.virtualshareholdermeeting.com/ENLC2025SM, at 10:00 a.m., Central Time. Only holders of common units representing limited liability company interests of EnLink (each such common unit, an “EnLink Unit,” and each such holder, an “EnLink unitholder”) of record as of December 23, 2024 (the “Record Date”) are entitled to receive this notice and to vote at the EnLink Special Meeting or any adjournment or postponement of that meeting. The EnLink Special Meeting has been called for the following purposes:

1.      To consider and vote upon a proposal to approve the Agreement and Plan of Merger, dated as of November 24, 2024 (the “Merger Agreement”), by and among EnLink, ONEOK, Inc. (“ONEOK”), Elk Merger Sub I, L.L.C., a direct, wholly-owned subsidiary of ONEOK (“Merger Sub I”), Elk Merger Sub II, L.L.C., a direct, wholly-owned subsidiary of ONEOK (“Merger Sub II”), and EnLink Midstream Manager, LLC, the managing member of EnLink (the “Manager”), as it may be amended from time to time, a copy of which is attached as Annex A to the proxy statement/prospectus, and the Mergers (as defined below) contemplated by the Merger Agreement (the “Merger Proposal”); and

2.      To consider and vote upon a proposal to approve, on a non-binding advisory basis, the compensation that may be paid or become payable to EnLink’s named executive officers that is based on or otherwise relates to the Mergers (the “Non-Binding Advisory Compensation Proposal”).

EnLink does not intend to transact any other business at the EnLink Special Meeting or any adjournment or postponement thereof, except such business as may properly be brought before the EnLink Special Meeting by or at the direction of the board of directors of the Manager (the “EnLink Board”) in accordance with the Third Amended and Restated Operating Agreement of EnLink, dated as of October 15, 2024, as amended or supplemented from time to time. These items of business are described in the enclosed proxy statement/prospectus. Please refer to the attached documents, including the Merger Agreement and all other annexes and any documents incorporated by reference, for further information with respect to the business to be transacted at the EnLink Special Meeting. You are encouraged to read the entire document carefully before voting. In particular, please see the sections entitled “The Mergers” beginning on page 35 for a description of the transactions contemplated by the Merger Agreement and “Risk Factors” beginning on page 13 for an explanation of the risks associated with the Mergers and the other transactions contemplated by the Merger Agreement.

Approval of the Merger Proposal by the affirmative vote of the holders of a majority of the outstanding EnLink Units entitled to vote thereon is required to complete the Mergers, as contemplated by the Merger Agreement. EnLink unitholders will also be asked to approve the Non-Binding Advisory Compensation Proposal.

The EnLink Board has designated the close of business on December 23, 2024 as the Record Date for the purpose of determining the EnLink unitholders who are entitled to receive notice of, and to vote at, the EnLink Special Meeting and any adjournment or postponement of the meeting, unless a new record date is fixed in connection with any adjournment or postponement of the meeting. Only holders of record of EnLink Units at the close of business on the Record Date are entitled to notice of, and to vote at, the EnLink Special Meeting and at any adjournment or postponement of the meeting. For additional information regarding the EnLink Special Meeting, see the section entitled “Special Meeting of EnLink Unitholders” beginning on page 27 of the proxy statement/prospectus accompanying this notice.

Pursuant to the Merger Agreement, (i) Merger Sub I will merge with and into EnLink (the “First Merger”), with EnLink as the surviving company and (ii) promptly following the First Merger, but in any event on the same day as the First Merger and as part of the same overall transaction as the First Merger, at the effective time of the Second Merger (as defined below), EnLink, as the surviving entity in the First Merger, will merge with and into Merger Sub II (the “Second Merger” and, together with the First Merger, the “Mergers”), with Merger Sub II surviving the Second Merger as a direct, wholly-owned subsidiary of ONEOK.

The conflicts committee (the “EnLink Conflicts Committee”) of the EnLink Board unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement (as defined below), were in the best interests of EnLink and the EnLink unitholders other than ONEOK, Manager and their respective affiliates (the “EnLink Unaffiliated Unitholders”), (ii) approved the Merger Agreement and the Support Agreement and the transactions contemplated thereby, and the execution, delivery, and performance of such agreements and the transactions contemplated thereby, (iii) recommended that the EnLink Board approve the Merger Agreement and the Support Agreement and the transactions contemplated thereby, and the execution, delivery, and performance of such agreements and the transactions contemplated thereby, and (iv) recommended (A) that the EnLink Board resolve to direct that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders and (B) that the EnLink unitholders approve the Merger Agreement and the Mergers.

The EnLink Board (acting based in part upon the recommendation of the EnLink Conflicts Committee) unanimously (i) determined that the Mergers are in the best interests of EnLink and the EnLink unitholders, (ii) approved the Merger Agreement and the Support Agreement, the execution, delivery, and performance of such agreements and the transactions contemplated thereby, (iii) directed that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders, and (iv) recommended that the EnLink unitholders approve the Merger Agreement. The EnLink Conflicts Committee and the EnLink Board each recommend that EnLink unitholders vote “FOR” the Merger Proposal. The EnLink Board unanimously recommends that EnLink unitholders vote “FOR” the Non-Binding Advisory Compensation Proposal.

Properly executed proxy cards with no instructions indicated on the proxy card will be voted “FOR” the Merger Proposal and “FOR” the Non-Binding Advisory Compensation Proposal. The presence, in person or by proxy, of EnLink unitholders as of the Record Date representing a majority of outstanding EnLink Units is necessary to constitute a quorum for purposes of voting on the proposals during the EnLink Special Meeting. Abstention votes will count as present for purposes of establishing a quorum during the EnLink Special Meeting. Virtual attendance at the EnLink Special Meeting will constitute presence in person for the purpose of determining the presence of a quorum for the transaction of business at the EnLink Special Meeting. Even if you plan to attend the EnLink Special Meeting virtually, EnLink requests that you vote by Internet or telephone or complete, sign, date and return the enclosed proxy card in the accompanying envelope as promptly as possible to ensure that your EnLink Units will be represented and voted at the EnLink Special Meeting if you later decide not to or become unable to attend virtually.

Please vote as promptly as possible, whether or not you plan to attend the EnLink Special Meeting virtually. If your EnLink Units are held in the name of a broker, bank, or other nominee, please vote by following the instructions on the voting instruction form furnished by the broker, bank, or other nominee. If you hold your EnLink Units in your own name, submit a proxy to vote your EnLink Units as promptly as possible by (i) visiting the Internet site listed on the proxy card, (ii) calling the toll-free number listed on the proxy card or (iii) submitting your proxy card by mail by using the self-addressed, stamped envelope provided. Submitting a proxy will not prevent you from voting virtually, but it will help to secure a quorum and avoid added solicitation costs. Any eligible EnLink unitholder entitled to vote thereon and who is virtually present at the EnLink Special Meeting may vote, thereby revoking any previous proxy. In addition, a proxy may also be revoked in writing before the EnLink Special Meeting in the manner described in the accompanying proxy statement/prospectus.

If you have any questions concerning the Merger Proposal, the Non-Binding Advisory Compensation Proposal, the Mergers or the proxy statement/prospectus, would like additional copies or need help voting your EnLink Units, please contact EnLink’s proxy solicitor:

Innisfree M&A Incorporated
Unitholders may call toll free: (866) 239-1762
Banks and Brokers may call collect: (212) 750-5833

Dallas, Texas
December 30, 2024

ABOUT THIS PROXY STATEMENT/PROSPECTUS; ADDITIONAL INFORMATION

This document, which forms part of a registration statement on Form S-4 filed with the U.S. Securities and Exchange Commission (the “SEC”) by ONEOK, constitutes a prospectus of ONEOK under Section 5 of the Securities Act of 1933, as amended (the “Securities Act”), with respect to the shares of ONEOK Common Stock to be issued to EnLink unitholders pursuant to the Merger Agreement. This document also constitutes a proxy statement of EnLink under Section 14(a) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). It also constitutes a notice of meeting with respect to the EnLink Special Meeting.

You should rely only on the information contained in or incorporated by reference into this proxy statement/prospectus. ONEOK and EnLink have not authorized anyone to provide you with information that is different from that contained in or incorporated by reference into this proxy statement/prospectus. This proxy statement/prospectus is dated December 30, 2024. The information contained in this proxy statement/prospectus is accurate only as of that date or, in the case of information in a document incorporated by reference, as of the date of such document, unless the information specifically indicates that another date applies. Neither the mailing of this proxy statement/prospectus to EnLink unitholders nor the issuance by ONEOK of shares of ONEOK Common Stock pursuant to the Merger Agreement will create any implication to the contrary.

This proxy statement/prospectus does not constitute an offer to sell, or a solicitation of an offer to buy, any securities, or the solicitation of a proxy, in any jurisdiction to or from any person to whom it is unlawful to make any such offer or solicitation in such jurisdiction. ONEOK has supplied all information contained in this proxy statement/prospectus relating to ONEOK, and EnLink has supplied all such information relating to EnLink. ONEOK and EnLink have both contributed to the information related to the Mergers contained in this proxy statement/prospectus.

Except as otherwise specifically noted, or the context otherwise requires, as used in this proxy statement/prospectus:

•        “Effective Time” means the effective time of the Second Merger and as set forth in the Merger Agreement.

•        “EnLink” refers to EnLink Midstream, LLC, a Delaware limited liability company;

•        “EnLink Board” refers to the board of directors of Manager;

•        “EnLink Conflicts Committee” refers to the conflicts committee of the EnLink Board;

•        “EnLink Special Meeting” refers to the special meeting of EnLink unitholders;

•        “EnLink Units” refers to the common units representing limited liability company interests of EnLink;

•        “EnLink unitholders” refers to the holders of EnLink Units;

•        “First Merger” refers to the merger, pursuant to the Merger Agreement, of Merger Sub I with and into EnLink, with EnLink as the surviving company;

•        “Manager” refers to EnLink Midstream Manager, LLC, a Delaware limited liability company and the managing member of EnLink;

•        “Merger Agreement” refers to the Agreement and Plan of Merger, dated as of November 24, 2024, by and among ONEOK, EnLink, Merger Sub I, Merger Sub II, and Manager, as it may be amended from time to time;

•        “Merger Consideration” refers to the 0.1412 shares of ONEOK Common Stock per outstanding EnLink Unit that will be issued to EnLink unitholders in connection with the Mergers;

•        “Merger Sub I” refers to Elk Merger Sub I, L.L.C., a Delaware limited liability company and direct, wholly-owned subsidiary of ONEOK;

•        “Merger Sub II” refers to Elk Merger Sub II, L.L.C., a Delaware limited liability company and direct, wholly-owned subsidiary of ONEOK;

•        “Merger Subs” refers to, collectively, Merger Sub I and Merger Sub II;

•        “Mergers” refers to, collectively, the First Merger and the Second Merger;

•        “ONEOK” refers to ONEOK, Inc., an Oklahoma corporation;

•        “ONEOK Board” refers to the board of directors of ONEOK;

•        “ONEOK Common Stock” refers to the common stock of ONEOK, par value $0.01 per share;

•        “Second Merger” refers to the merger, pursuant to the Merger Agreement and promptly following the First Merger, but in any event on the same day as the First Merger and as part of the same overall transaction as the First Merger, at the Effective Time, of EnLink, as the surviving entity in the First Merger, with and into Merger Sub II, with Merger Sub II surviving the Second Merger as a direct, wholly-owned subsidiary of ONEOK; and

•        references to directors and executive officers of EnLink refer to the directors and executive officers of Manager, the managing member of EnLink.

As permitted under the rules of the SEC, this document incorporates by reference important business and financial information about ONEOK and EnLink from other documents filed with the SEC that are not included in or delivered with this document. Please read the section titled “Where You Can Find More Information.” You can obtain any of the documents incorporated by reference into this document from the SEC’s website at www.sec.gov. This information is also available to you without charge upon your request in writing or by telephone from ONEOK or EnLink at the following addresses and telephone numbers:

Please note that copies of the documents provided to you will not include exhibits, unless the exhibits are specifically incorporated by reference into the documents or this document.

To obtain timely delivery of these documents before the EnLink Special Meeting, EnLink unitholders must request the information no later than January 23, 2025 (which is five business days before the date of the EnLink Special Meeting).

You may also obtain certain of these documents at ONEOK’s website, www.oneok.com, and at EnLink’s website, www.enlink.com. Except as expressly provided herein, none of the information contained on or accessible through the websites of ONEOK or EnLink is incorporated by reference into this document.

In addition, if you have questions about the Mergers or this proxy statement/prospectus, would like additional copies of this proxy statement/prospectus or need to obtain letters of transmittal (which are being mailed to EnLink unitholders) or other information related to the proxy solicitation, contact: Innisfree M&A Incorporated, the proxy solicitor for EnLink, toll-free at (866) 239-1762 or, for brokers and banks, collect at (212) 750-5833. You will not be charged for any of these documents that you request.

TABLE OF CONTENTS

QUESTIONS AND ANSWERS ABOUT THE MERGERS AND THE ENLINK SPECIAL MEETING

The following questions and answers briefly address some commonly asked questions about the Mergers and the EnLink Special Meeting. You are urged to read the remainder of this document carefully because the information in this section may not provide all the information that might be important to you in determining how to vote. Additional important information is also contained in the annexes to, and the documents incorporated by reference in, this document.

Q:     Why am I receiving these materials?

A:     You are receiving this proxy statement/prospectus because ONEOK and EnLink have entered into the Merger Agreement, pursuant to which, on the terms and subject to the fulfillment or, to the extent permissible under applicable law, waiver of the conditions included in the Merger Agreement, (i) in the First Merger, Merger Sub I will merge with and into EnLink, the separate existence of Merger Sub I will cease and EnLink will survive and continue to exist and (ii) in the Second Merger, promptly following the First Merger, but in any event on the same day as the First Merger and as part of the same overall transaction as the First Merger, at the Effective Time (as defined below), EnLink, as the surviving entity in the First Merger, will merge with and into Merger Sub II, the separate existence of EnLink will cease and Merger Sub II shall survive and continue to exist as a direct, wholly-owned subsidiary of ONEOK. As referred to in this proxy statement/prospectus, the “First Merger Effective Time” means the effective time of the First Merger and as set forth in the Merger Agreement. As referred to in this proxy statement/prospectus, the “Effective Time” means the effective time of the Second Merger and as set forth in the Merger Agreement. The Merger Agreement governs the terms of the Mergers and is attached to this proxy statement/prospectus as Annex A.

In order to complete the Mergers, among other things, EnLink unitholders must approve the Merger Agreement and the Mergers contemplated thereby in accordance with Delaware law.

This proxy statement/prospectus serves as both the proxy statement through which EnLink will solicit proxies to obtain the necessary unitholder approvals for the Mergers and the prospectus by which ONEOK will issue shares of ONEOK Common Stock as consideration in the Mergers. This proxy statement/prospectus, which you should carefully read in its entirety, contains important information about the EnLink Special Meeting, the Mergers and other matters.

Q:     What will happen in the Mergers?

A:     The Merger Agreement sets forth the terms and conditions of the proposed Mergers. Under the Merger Agreement, (i) in the First Merger, Merger Sub I will merge with and into EnLink, the separate existence of Merger Sub I will cease and EnLink will survive and continue to exist and (ii) in the Second Merger, promptly following the First Merger, but in any event on the same day as the First Merger and as part of the same overall transaction as the First Merger, at the Effective Time, EnLink, as the surviving entity in the First Merger, will merge with and into Merger Sub II, the separate existence of EnLink will cease and Merger Sub II shall survive and continue to exist as a direct, wholly-owned subsidiary of ONEOK.

The Merger Agreement is attached to this proxy statement/prospectus as Annex A. For additional information regarding the proposed Mergers, their effects and the other transactions contemplated by the Merger Agreement, please see the section entitled “The Mergers.”

Q:     When and where is the EnLink Special Meeting? How can I attend the EnLink Special Meeting?

A:     The EnLink Special Meeting will be held virtually at www.virtualshareholdermeeting.com/ENLC2025SM, on January 30, 2025, at 10:00 a.m., Central Time. Online access will begin at 9:45 a.m., Central Time, and EnLink encourages its unitholders to access the meeting prior to the start time. The EnLink Special Meeting will be held in a virtual meeting format only, via live webcast, and there will not be a physical meeting location.

EnLink unitholders as of close of business on December 23, 2024 (the “Record Date”) may attend, vote and submit questions virtually at the EnLink Special Meeting by logging in at www.virtualshareholdermeeting.com/ENLC2025SM. To log in, EnLink unitholders (or their authorized

representatives) will need the control number provided on their proxy card, voting instruction form or notice. If you are not an EnLink unitholder or do not have a control number, you may still access the meeting as a guest, but you will not be able to participate.

Even if you plan to attend the EnLink Special Meeting virtually, EnLink recommends that you submit a proxy with respect to your units in advance as described above so that your vote will be counted if you later decide not to or become unable to attend the EnLink Special Meeting.

Q:     Who is entitled to vote at the EnLink Special Meeting?

A:     The Record Date for the EnLink Special Meeting is December 23, 2024. All EnLink unitholders who held EnLink Units at the close of business on the Record Date are entitled to receive notice of, and to vote at, the EnLink Special Meeting. Each such EnLink unitholder is entitled to cast one vote on each matter properly brought before the EnLink Special Meeting for each EnLink Unit that such holder owned of record as of the Record Date. Attendance at the EnLink Special Meeting, which will be held virtually, is not required for an EnLink unitholder’s units to be voted. For additional information on how to submit a proxy for your EnLink Units without attending the EnLink Special Meeting, please see the section entitled “Special Meeting of EnLink Unitholders — Voting at the EnLink Special Meeting.”

Q:     What are EnLink unitholders being asked to vote on?

A:     The EnLink unitholders are being asked to consider and vote on proposals to (i) approve the Merger Agreement and the Mergers contemplated thereby (the “Merger Proposal”), pursuant to which EnLink unitholders will receive, for each EnLink Unit that they own as of immediately prior to the First Merger Effective Time (except for any EnLink Units that are owned immediately prior to the First Merger Effective Time by EnLink as treasury units, if any, or by the Manager, ONEOK, Merger Sub I, or Merger Sub II (collectively, the “Excluded Units”)), 0.1412 shares of ONEOK Common Stock, and (ii) approve, on a non-binding advisory basis, the compensation that may be paid or become payable to EnLink’s named executive officers that is based on or otherwise relates to the Mergers (the “Non-Binding Advisory Compensation Proposal”).

Q:     How important is my vote as an EnLink unitholder?

A:     Your vote is very important. The proposed Mergers between ONEOK and EnLink cannot be completed without the approval of the Merger Proposal by the affirmative vote of a majority of the outstanding EnLink Units entitled to vote at the EnLink Special Meeting. The EnLink Conflicts Committee and the EnLink Board each unanimously recommends that EnLink unitholders vote “FOR” the Merger Proposal. The EnLink Board unanimously recommends that EnLink unitholders vote “FOR” the Non-Binding Advisory Compensation Proposal. You are encouraged to submit a proxy as soon as possible. Approval of the Non-Binding Advisory Compensation Proposal is not a condition to the consummation of the Mergers.

Q:     What constitutes a quorum and what vote is required to approve each proposal at the EnLink Special Meeting?

A:     EnLink unitholders holding a majority of the outstanding EnLink Units entitled to vote at the EnLink Special Meeting must be represented at the EnLink Special Meeting in person or by proxy in order to constitute a quorum. Virtual attendance at the EnLink Special Meeting will constitute presence in person for the purpose of determining the presence of a quorum for the transaction of business at the EnLink Special Meeting.

The Merger Proposal.    Approval of the Merger Proposal requires the affirmative vote of holders of a majority of the outstanding EnLink Units entitled to vote on the proposal. Accordingly, an EnLink unitholder’s abstention from voting or the failure of an EnLink unitholder to vote (including the failure of an EnLink unitholder who holds EnLink Units in “street name” through a bank, broker or other nominee to give voting instructions to the bank, broker or other nominee) will have the same effect as a vote “against” the Merger Proposal.

The Non-Binding Advisory Compensation Proposal.    Approval of the Non-Binding Advisory Compensation Proposal requires the affirmative vote of holders of a majority of the outstanding EnLink Units entitled to vote on the proposal. Accordingly, an EnLink unitholder’s abstention from voting or the failure of an EnLink

unitholder to vote (including the failure of an EnLink unitholder who holds EnLink Units in “street name” through a bank, broker or other nominee to give voting instructions to the bank, broker or other nominee) will have the same effect as a vote “against” the Non-Binding Advisory Compensation Proposal. As an advisory vote, this proposal is not binding upon EnLink, the EnLink Board, ONEOK or the ONEOK Board, and approval of this proposal is not a condition to completion of the Mergers.

Q:     Have any EnLink unitholders agreed to vote their units in favor of the Merger Proposal or the Non-Binding Advisory Compensation Proposal?

A:     Yes. At the close of business on December 23, 2024, the Record Date, ONEOK beneficially owned and is entitled to vote approximately 200,340,753 EnLink Units, representing approximately 43.8% of the EnLink Units outstanding on that date. Pursuant to the terms of a Support Agreement, dated as of November 24, 2024, by and between ONEOK and EnLink (the “Support Agreement”), ONEOK has irrevocably agreed to vote such units in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal. For additional information regarding the Support Agreement, please see the section entitled “The Mergers — Support Agreement.”

Q:     What will EnLink unitholders receive if the Mergers are completed?

A:     If the Mergers are completed, each eligible EnLink Unit outstanding at the First Merger Effective Time will automatically be converted into the right to receive 0.1412 duly authorized and validly issued shares of ONEOK Common Stock (such ratio, the “Exchange Ratio”). Each EnLink unitholder will receive cash in lieu of any fractional share of ONEOK Common Stock that such EnLink unitholder would otherwise be entitled to receive in the Mergers.

Because ONEOK will issue a fixed number of shares of ONEOK Common Stock in exchange for each EnLink Unit, the value of the Merger Consideration that EnLink unitholders will receive in the Mergers will depend on the market price of shares of ONEOK Common Stock at the First Merger Effective Time. The market price of shares of ONEOK Common Stock that EnLink unitholders receive at the First Merger Effective Time could be greater than, less than or the same as the market price of shares of ONEOK Common Stock on the date of this proxy statement/prospectus or at the time of the EnLink Special Meeting. Accordingly, you should obtain current market quotations for ONEOK Common Stock and EnLink Units before deciding how to vote with respect to the Merger Proposal. ONEOK Common Stock is traded on the New York Stock Exchange (“NYSE”) under the symbol “OKE.” EnLink Units are traded on the NYSE under the symbol “ENLC.”

For additional information regarding the Merger Consideration to be received by EnLink unitholders if the Mergers are completed, please see the section entitled “The Merger Agreement — Merger Consideration.”

Q:     What equity stake will EnLink unitholders hold in ONEOK immediately following the Mergers?

A:     Based on the number of issued and outstanding shares of ONEOK Common Stock and EnLink Units as of December 23, 2024, and the Exchange Ratio of 0.1412 shares of ONEOK Common Stock for each EnLink Unit, holders of EnLink Units as of immediately prior to the First Merger Effective Time would hold, in the aggregate, approximately 5.9% of the issued and outstanding shares of ONEOK Common Stock immediately following the First Merger Effective Time. The exact equity stake of EnLink unitholders in ONEOK immediately following the First Merger Effective Time will depend on the number of shares of ONEOK Common Stock and EnLink Units issued and outstanding immediately prior to the First Merger Effective Time.

For additional information regarding the equity stake of EnLink unitholders in ONEOK following the Mergers, please see the sections entitled “The Merger Agreement — Merger Consideration” and “The Merger Agreement — Exchange of Units.”

Q:     Will EnLink equity and other long-term incentive awards be affected by the Mergers?

A:     Upon the completion of the Mergers, outstanding EnLink equity awards will be affected as described below.

EnLink equity awards that are outstanding immediately prior to the First Merger Effective Time will be subject to the following treatment at the First Merger Effective Time:

•        each award of restricted incentive units of EnLink (each, an “EnLink RIU” and such award, an “EnLink RIU Award”), whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock equal to the number of EnLink Units subject to such EnLink RIU Award immediately prior to the First Merger Effective Time multiplied by the Exchange Ratio, rounded up or down to the nearest whole share of ONEOK Common Stock and otherwise subject to the same terms and conditions (including as to vesting and forfeiture) as were applicable to such EnLink RIU Award immediately prior to the First Merger Effective Time; and

•        each award of performance units of EnLink (each, an “EnLink PU” and such award, an “EnLink PU Award”), whether vested or unvested, that is outstanding immediately prior to the First Merger Effective Time, will, as of the First Merger Effective Time, be assumed by ONEOK and converted into a time-based restricted stock unit award with respect to ONEOK Common Stock relating to a number of shares of ONEOK Common Stock with respect to each tranche of the EnLink PU Award as identified in the applicable award agreement (an “EnLink PU Tranche”) equal to the number of EnLink Units subject to such EnLink PU Tranche immediately prior to the First Merger Effective Time (determined as set forth below and, for those individuals who experienced a “Qualifying Termination” or “Retirement” (as such terms are defined in the applicable award agreement) prior to the GIP Interest Acquisition (as defined below), taking into account any applicable proration provisions) multiplied by the Exchange Ratio, rounded up or down to the nearest whole share of ONEOK Common Stock and otherwise subject to the same terms and conditions (including as to vesting and forfeiture, except any performance-based vesting condition will not apply) as were applicable to such EnLink PU Award immediately prior to the First Merger Effective Time. For purposes of determining the number of EnLink Units subject to each EnLink PU Tranche, the following shall apply:

•        for each EnLink PU Tranche that vests based on performance metrics tied to the relative total shareholder return of EnLink (each, an “EnLink PU TSR Tranche”) and each EnLink PU Tranche that vests based on performance metrics tied to the cash flow of EnLink (each, an “EnLink PU DCF Tranche”) for which the performance period has closed prior to the date on which the closing of the Mergers (the “closing”) actually occurs (such date, the “closing date”), the number of EnLink Units shall be determined based on the actual achievement of the performance criteria attained through the end of the performance period, as previously certified by the EnLink Board or a committee thereof or, if not yet certified, as determined by the EnLink Board in good faith in the ordinary course of business consistent with past practice;

•        for each EnLink PU TSR Tranche and EnLink PU DCF Tranche for which the performance period has commenced but not closed as of the closing date, the number of EnLink Units shall be determined based on the “target” level of performance; and

•        for each EnLink PU TSR Tranche and EnLink PU DCF Tranche for which the performance period has not yet commenced as of the closing date, the number of EnLink Units shall be determined based on the “target” level of performance.

For additional information regarding the EnLink equity and other long-term incentive awards, please see the section entitled “The Mergers — Interests of Certain EnLink Directors and Executive Officers in the Mergers — Treatment of EnLink Equity Awards.”

Q:     How do the EnLink Conflicts Committee and the EnLink Board recommend that I vote at the EnLink Special Meeting?

A:     The EnLink Conflicts Committee and the EnLink Board each unanimously recommends that you vote “FOR” the Merger Proposal. The EnLink Board unanimously recommends that EnLink Unitholders vote “FOR” the Non-Binding Advisory Compensation Proposal. For additional information regarding the recommendation of the EnLink Conflicts Committee and the EnLink Board, please see the section entitled “The Mergers — Recommendation of the EnLink Conflicts Committee and the EnLink Board and their Reasons for the Mergers.”

Q:     How many votes do I have for the EnLink Special Meeting?

A:     Each EnLink unitholder is entitled to one vote for each EnLink Unit held of record as of the close of business on the Record Date for each proposal. As of the close of business on the Record Date, there were 457,079,545 outstanding EnLink Units.

Q:     What happens if the Mergers are not completed?

A:     If the EnLink unitholders do not approve the Merger Proposal or if the Mergers are not completed for any other reason, EnLink unitholders will not receive any Merger Consideration for their EnLink Units in connection with the Mergers. Instead, ONEOK and EnLink will each remain independent public companies. The ONEOK Common Stock will continue to be listed and traded on the NYSE, and the EnLink Units will continue to be listed and traded on the NYSE. Additionally, if the Merger Proposal is not approved by EnLink unitholders or if the Mergers are not completed for any other reason, ONEOK will not issue shares of ONEOK Common Stock to EnLink unitholders. If the Merger Agreement is terminated under certain specified circumstances, EnLink may be required to pay ONEOK a termination fee of $143,978,000 or to reimburse ONEOK’s expenses up to $10.0 million, and ONEOK may be required to reimburse EnLink’s expenses up to $10.0 million. For additional information regarding termination fees, please see the section entitled “The Merger Agreement — Termination Fee.”

Q:     What happens if the Non-Binding Advisory Compensation Proposal is not approved by EnLink unitholders?

A:     This vote is advisory and non-binding, and the Mergers are not conditioned or dependent upon the approval of the Non-Binding Advisory Compensation Proposal by EnLink unitholders. However, EnLink and ONEOK value the opinions of EnLink unitholders, and ONEOK expects to consider the outcome of the vote, along with other relevant factors, when considering future executive compensation, assuming the Mergers are completed. Because the executive compensation to be paid in connection with the Mergers is based on the terms of the Merger Agreement as well as the contractual arrangements between Manager and its named executive officers, subject to the contractual conditions applicable thereto, such compensation will be payable, regardless of the outcome of this advisory vote if the Merger Proposal is approved. However, EnLink seeks the support of its unitholders and believes that unitholder support is appropriate because Manager has a comprehensive executive compensation program designed to link the compensation of its named executive officers with EnLink’s performance and the interests of EnLink unitholders.

Q:     What is a proxy?

A:     A unitholder’s legal designation of another person to vote shares or units of such unitholder’s units at a special or annual meeting is referred to as a proxy. The document used to designate a proxy to vote your units is called a proxy card.

Q:     How can I vote my EnLink Units and participate at the EnLink Special Meeting?

A:     If you are an EnLink unitholder of record as of the close of business on the Record Date, you may submit your proxy before the EnLink Special Meeting in one of the following ways:

•        Telephone-use the toll-free number shown on your proxy card;

•        Internet-visit the website shown on your proxy card to vote via the Internet; or

•        Mail-complete, sign, date and return the enclosed proxy card in the enclosed postage-paid envelope.

If you are an EnLink unitholder of record, you may also cast your vote virtually at the EnLink Special Meeting by following the instructions at www.virtualshareholdermeeting.com/ENLC2025SM. If you decide to attend the EnLink Special Meeting virtually and vote at the meeting, your vote will revoke any proxy previously submitted.

The EnLink Special Meeting will begin promptly at 10:00 a.m., Central Time, on January 30, 2025. EnLink encourages its unitholders to access the meeting prior to the start time leaving ample time for check-in. Please follow the instructions as outlined in this proxy statement/prospectus.

Even if you plan to attend the EnLink Special Meeting virtually, EnLink recommends that you submit your proxy with respect to your EnLink Units in advance as described below so that your vote will be counted if you later decide not to or become unable to attend the EnLink Special Meeting.

Q:     How can I vote my EnLink Units without attending the EnLink Special Meeting?

A:     Whether you hold your EnLink Units directly as a unitholder of record of EnLink or beneficially in “street name,” you may direct your vote by proxy without attending the EnLink Special Meeting. You can submit your proxy by mail, over the Internet or by telephone by following the instructions provided in the enclosed proxy card. Please note that if you hold EnLink Units beneficially in “street name,” you should follow the voting instructions provided by your bank, broker or other nominee.

For additional information regarding voting procedures, please see the section entitled “EnLink Special Meeting.”

Q:     What is the difference between holding units as a unitholder of record and as a beneficial owner of units held in “street name?”

A:     If your units are held in “street name” in a stock brokerage account or by a bank or other nominee, you must provide the record holder of your units with instructions on how to vote your units. Please follow the voting instructions provided by your broker, bank or other nominee. Please note that you may not vote units held in street name by returning a proxy card directly to EnLink or by voting virtually at the EnLink Special Meeting, unless you provide a “legal proxy,” which you must obtain from your broker, bank or other nominee.

Q:     If my EnLink Units are held in “street name” by my bank, broker or other nominee, will my bank, broker or other nominee automatically vote those units for me?

A:     Under the rules of the NYSE, your bank, broker or other nominee will only be permitted to vote your EnLink Units on “non-routine” matters if you instruct your bank, broker or other nominee how to vote. All of the proposals scheduled for consideration at the EnLink Special Meeting are “non-routine” matters. As a result, if you fail to provide voting instructions to your broker, bank or other nominee, your units will not be counted as present at the EnLink Special Meeting for purposes of determining a quorum and will not be voted on any of the proposals. To make sure that your units are voted on each of the proposals, you should instruct your bank, broker or other nominee how you wish to vote your units in accordance with the procedures provided by your bank, broker or other nominee regarding the voting of your units.

The effect of an EnLink unitholder not instructing its, his or her bank, broker or other nominee how such unitholder wishes to vote its, his or her units will be the same as a vote “against” the Merger Proposal and “against” the Non-Binding Advisory Compensation Proposal.

Q:     What should I do if I receive more than one set of voting materials for the EnLink Special Meeting?

A:     If you hold EnLink Units in “street name” and also directly in your name as a unitholder of record or otherwise, or if you hold EnLink Units in more than one brokerage account, you may receive more than one set of voting materials relating to the EnLink Special Meeting.

Record Holders.    For units held directly, please complete, sign, date and return each proxy card, or you may cast your vote by telephone or Internet as provided on each proxy card, or otherwise follow the voting instructions provided in this proxy statement/prospectus in order to ensure that all of your EnLink Units are voted.

“Street name” Holders.    For units held in “street name” through a bank, broker or other nominee, you should follow the procedures provided by your bank, broker or other nominee to vote your units.

Q:     If an EnLink unitholder gives a proxy, how are the EnLink Units voted?

A:     Regardless of the method you choose to vote, the individuals named on the enclosed proxy card will vote your EnLink Units in the way that you indicate. When completing the proxy card or the Internet or telephone processes, you may specify whether your EnLink Units should be voted for or against, or abstain from voting on, all, some or none of the specific items of business to come before the EnLink Special Meeting.

Q:     How will my EnLink Units be voted if I return a blank proxy?

A:     If you sign, date and return your proxy card and do not indicate how you want your EnLink Units to be voted, then your EnLink Units will be voted “FOR” the Merger Proposal and “FOR” the Non-Binding Advisory Compensation Proposal.

Q:     Can I change my vote of EnLink Units after I have submitted my proxy?

A:     Any EnLink unitholder giving a proxy has the right to revoke it before the proxy is voted at the EnLink Special Meeting by:

•        subsequently submitting a new proxy, whether by submitting a new proxy card or by submitting a proxy via the Internet or telephone, that is received by the deadline specified on the accompanying proxy card;

•        giving written notice of your revocation to EnLink’s Secretary;

•        voting virtually at the EnLink Special Meeting; or

•        revoking your proxy and voting at the EnLink Special Meeting.

Your attendance at the EnLink Special Meeting will not revoke your proxy unless you give written notice of revocation to EnLink’s Secretary before your proxy is exercised or unless you vote your units in person at the EnLink Special Meeting.

Execution or revocation of a proxy will not in any way affect your right to attend the EnLink Special Meeting and vote. Written notices of revocation and other communications with respect to the revocation of proxies should be addressed to:

EnLink Midstream, LLC
Attn: Secretary
1722 Routh Street, Suite 1300
Dallas, Texas 75201
(214) 953-9500

For additional information regarding revoking your proxy prior to the EnLink Special Meeting, please see the section entitled “Special Meeting of EnLink Unitholders — Revocation of Proxies.”

Q:     If I hold my EnLink Units in “street name,” can I change my voting instructions after I have submitted voting instructions to my bank, broker or other nominee?

A:     If your EnLink Units are held in the name of a bank, broker or other nominee and you previously provided voting instructions to your bank, broker or other nominee, you should follow the instructions provided by your bank, broker or other nominee to revoke or change your voting instructions.

Q:     Where can I find the voting results of the EnLink Special Meeting?

A:     The preliminary voting results for the EnLink Special Meeting will be announced at the EnLink Special Meeting. In addition, within four business days of the EnLink Special Meeting, EnLink intends to file the final voting results of its meeting with the SEC on a Current Report on Form 8-K.

Q:     Do EnLink unitholders have appraisal rights or dissenters’ rights?

A:     No. Under the Delaware Limited Liability Company Act (the “DLLCA”), EnLink unitholders are not entitled to appraisal or dissenters’ rights in connection with the Mergers.

Q:     As an EnLink unitholder, are there any risks that I should consider in deciding whether to vote for the approval of the Merger Proposal?

A:     Yes. You should read and carefully consider the risk factors set forth in “Risk Factors.” You also should read and carefully consider the risk factors of ONEOK and EnLink contained in the reports of ONEOK and EnLink which are incorporated by reference into this proxy statement/prospectus.

Q:     Do any of the officers or directors of EnLink have interests in the Mergers that may differ from or be in addition to my interests as an EnLink unitholder?

A:     Yes. In considering the recommendation of the EnLink Board and the EnLink Conflicts Committee that EnLink unitholders vote to approve the Merger Proposal, EnLink unitholders should be aware that certain of EnLink’s directors and executive officers have interests in the Mergers that are different from, or in addition to, the interests of EnLink unitholders generally. The EnLink Board and the EnLink Conflicts Committee were aware of and considered these differing interests, to the extent such interests existed at the time, among other matters, in evaluating and negotiating the terms and conditions of the Merger Agreement and the Mergers and each unanimously recommended that the Merger Agreement be approved by EnLink unitholders. For additional information regarding the interests of EnLink’s directors and officers in the Mergers, please see the section entitled “The Mergers — Interests of Certain EnLink Directors and Executive Officers in the Mergers.”

Q:     What happens if I sell my EnLink Units after the Record Date but before the EnLink Special Meeting?

A:     The Record Date is earlier than the date of the EnLink Special Meeting. If you transfer your EnLink Units after the Record Date but before the EnLink Special Meeting, you will, unless special arrangements are made, retain your right to vote at the EnLink Special Meeting.

Q:     Who will solicit and pay the cost of soliciting proxies in connection with the EnLink Special Meeting?

A:     The EnLink Board is soliciting your proxy in connection with the EnLink Special Meeting, and EnLink will bear the cost of soliciting such proxies, however ONEOK and EnLink will each bear and pay one half of the expenses incurred in connection with the filing, printing and mailing this proxy statement/prospectus. EnLink has retained Innisfree M&A Incorporated as proxy solicitor to assist with the solicitation of proxies in connection with the EnLink Special Meeting. Solicitation initially will be made by mail. Forms of proxies and proxy materials may also be distributed through banks, brokers and other nominees to the beneficial owners of EnLink Units, in which case these parties will be reimbursed for their reasonable out-of-pocket expenses. Proxies may also be solicited in person or by telephone, facsimile, electronic mail, or other electronic medium by certain of EnLink’s directors, officers and employees, as applicable, without additional compensation.

EnLink also may be required to reimburse banks, brokers and other custodians, nominees and fiduciaries or their respective agents for their expenses in forwarding proxy materials to beneficial owners of EnLink Units. EnLink’s directors, officers and employees also may solicit proxies by telephone, by electronic means or in person. They will not be paid any additional amounts for soliciting proxies.

Q:     Will ONEOK hold a special meeting of shareholders to approve the Mergers?

A:     No. No action by any ONEOK shareholder is required under applicable law or otherwise to adopt the Merger Agreement or issue the Merger Consideration. ONEOK will not solicit the vote or call a special meeting of ONEOK shareholders for the adoption of the Merger Agreement or issuance of the Merger Consideration. ONEOK shareholders are not being asked for a proxy and ONEOK shareholders are requested not to send ONEOK a proxy.

Q:     What are the expected U.S. federal income tax consequences of the Mergers to EnLink’s U.S. unitholders?

A:     The parties intend for the Mergers, taken together, to be treated as a tax-free reorganization under Section 368(a) of the Internal Revenue Code of 1986, as amended (the “Code”). ONEOK and EnLink intend to report the Mergers, taken together, consistent with such treatment. Assuming the Mergers are so treated, a U.S. holder (as defined in the section entitled “Material U.S. Federal Income Tax Consequences”) generally will not recognize any gain or loss for U.S. federal income tax purposes upon the exchange of EnLink Units for shares of ONEOK Common Stock pursuant to the First Merger, except with respect to any cash received in lieu of fractional shares of ONEOK Common Stock.

It is a condition to EnLink’s and ONEOK’s obligations to complete the Mergers that EnLink receive an opinion from Baker Botts L.L.P., counsel to EnLink, or another nationally recognized tax counsel reasonably acceptable to EnLink and ONEOK (or if any such counsel is unable to deliver such opinion, Kirkland & Ellis LLP, counsel to ONEOK) that the Mergers, taken together, should qualify as a “reorganization” within the meaning of Section 368(a) of the Code. However, none of the parties to the Merger Agreement have sought or intend to seek any ruling from the Internal Revenue Service (the “IRS”) regarding the qualification of the Mergers, taken together, as a reorganization within the meaning of Section 368(a) of the Code, and there can be no assurances that the IRS will agree with the opinion from counsel.

For additional information regarding the U.S. federal income tax consequences of the Mergers, please see the section entitled “Material U.S. Federal Income Tax Consequences.” Each EnLink unitholder is strongly urged to consult with a tax advisor to determine the particular U.S. federal, state or local or non-U.S. income or other tax consequences of the Mergers.

Q:     What are the expected U.S. federal income tax consequences for EnLink’s U.S. unitholders of the ownership of shares of ONEOK Common Stock after the Mergers are completed?

A:     ONEOK is classified as a corporation for U.S. federal income tax purposes and is subject to U.S. federal income tax on its taxable income. A distribution of cash by ONEOK to a shareholder that is a U.S. holder will generally be included in such U.S. holder’s income as dividend income to the extent of ONEOK’s current or accumulated “earnings and profits” as determined under U.S. federal income tax principles. Distributions of cash in excess of ONEOK’s current and accumulated earnings and profits will be treated as a non-taxable return of capital reducing a U.S. holder’s adjusted tax basis in such U.S. holder’s shares of ONEOK Common Stock and, to the extent the distribution exceeds such U.S. holder’s adjusted tax basis, as capital gain from the sale or exchange of such shares of ONEOK Common Stock.

Upon the sale, exchange, certain redemptions or other taxable dispositions of shares of ONEOK Common Stock received in the Mergers, a U.S. holder will generally recognize capital gain or loss equal to the difference between (i) the amount of cash and the fair market value of any other property received upon such taxable disposition of shares of ONEOK Common Stock and (ii) the U.S. holder’s adjusted tax basis in such shares of ONEOK Common Stock.

For additional information regarding the U.S. federal income tax consequences of owning and disposing of ONEOK Common Stock received in the Mergers, see the section entitled “Material U.S. Federal Income Tax Consequences.”

Q:     When are the Mergers expected to be completed?

A:     Subject to the satisfaction or, to the extent permissible under applicable law, waiver of the closing conditions described under “The Merger Agreement — Conditions to the Completion of the Mergers,” including the approval of the Merger Proposal, the Mergers are expected to close in the first quarter of 2025. However, neither ONEOK nor EnLink can predict the actual date on which the Mergers will be completed, or if the Mergers will be completed at all, because completion of the Mergers are subject to conditions and factors outside the control of either company. ONEOK and EnLink hope to complete the Mergers as soon as reasonably practicable. In addition, if the Mergers are not completed by May 23, 2025, either ONEOK or EnLink may choose not to proceed with the Mergers by terminating the Merger Agreement.

Q:     What are the conditions to completion of the Mergers?

A:     The Mergers are subject to a number of conditions to closing as specified in the Merger Agreement. These closing conditions include, among others, (i) the approval of the Merger Proposal by the EnLink unitholders; (ii) no applicable law, injunction, judgment or ruling enacted, promulgated, issued, entered, amended or enforced by any governmental authority shall be in effect enjoining, restraining, preventing or prohibiting consummation of the transactions contemplated by the Merger Agreement or making the consummation of the transactions contemplated by the Merger Agreement illegal; (iii) the registration statement on Form S-4, of which this proxy statement/prospectus forms a part, has become effective under the Securities Act and no stop order suspending the effectiveness of the registration statement has been issued and no proceedings for that purpose have been initiated or threatened by the SEC; (iv) the shares of ONEOK Common Stock deliverable to the EnLink unitholders as contemplated by the Merger Agreement have been approved for listing on the NYSE, subject to official notice of issuance; and (v) the receipt by EnLink, on the closing date, but before the First Merger Effective Time, of an opinion from nationally recognized tax counsel concluding that, on the basis of facts, representations and assumptions set forth or referred to in such opinion, for U.S. federal income tax purposes, the Mergers, taken together, should qualify as a “reorganization” within the meaning of Section 368(a) of the Code. For additional information regarding the conditions to completion of the Mergers, please see the section entitled “The Merger Agreement — Conditions to the Completion of the Mergers.”

Q:     How will I receive the Merger Consideration to which I am entitled?

A:     If you hold your EnLink Units through The Depository Trust Company (“DTC”), you will not be required to take any specific actions to exchange your EnLink Units for shares of ONEOK Common Stock. After the completion of the Mergers, EnLink Units held through DTC in book-entry form will be automatically exchanged for shares of ONEOK Common Stock in book-entry form and an exchange agent (the “Exchange Agent”) selected by the parties will deliver to you a check in the aggregate amount of cash to be paid in lieu of any fractional share of ONEOK Common Stock to which you would otherwise be entitled immediately prior to the First Merger Effective Time. If you hold your EnLink Units in certificated form, or in book-entry form but not through DTC, after receiving the proper documentation from you, following the First Merger Effective Time, the Exchange Agent will deliver to you the ONEOK Common Stock and a check in the aggregate amount of cash to be paid in lieu of any fractional share of ONEOK Common Stock to which you would otherwise be entitled immediately prior to the First Merger Effective Time. For additional information, please see the section entitled “The Merger Agreement — Exchange of Units.”

Q:     What should I do now?

A:     You should read this proxy statement/prospectus carefully and in its entirety, including the annexes, and return your completed, signed and dated proxy card by mail in the enclosed postage-paid envelope, or you may submit your voting instructions by telephone or over the Internet as soon as possible so that your EnLink Units will be voted in accordance with your instructions.

Q:     Whom do I call if I have questions about the EnLink Special Meeting or the Mergers?

A:     If you are an EnLink unitholder and have questions about the EnLink Special Meeting or the Mergers, or desire additional copies of this proxy statement/prospectus or additional proxy cards, you may contact:

Innisfree M&A Incorporated
Unitholders may call toll free: (866) 239-1762
Banks and Brokers may call collect: (212) 750-5833

RISK FACTORS

In deciding how to vote, EnLink unitholders should carefully consider the following risk factors, all of the information contained in or incorporated by reference herein, including but not limited to, the matters addressed in the section titled “Cautionary Statement Regarding Forward-Looking Statements” and the risks associated with each of the businesses of ONEOK and EnLink included in their respective Annual Reports on Form 10-K for the year ended December 31, 2023, as updated by subsequent Quarterly Reports on Form 10-Q, all of which are filed with the SEC and incorporated by reference into this proxy statement/prospectus. Realization of any of the risks described below, any of the events described under “Cautionary Statement Regarding Forward-Looking Statements” or any of the risks or events described in the documents incorporated by reference could have a material adverse effect on ONEOK’s or EnLink’s business, financial condition, cash flows and results of operations and could result in a decline in the trading prices of their respective common stock or common units.

Risks Factors Related to the Mergers

Because the market price of ONEOK Common Stock will fluctuate prior to the consummation of the Mergers, EnLink unitholders cannot be sure of the market value of ONEOK Common Stock that they will receive in the Mergers. In addition, because the Exchange Ratio is fixed, the number of shares of ONEOK Common Stock to be received by EnLink unitholders in connection with the Mergers will not change between the date of this proxy statement/prospectus and the time the Mergers are completed to reflect changes in the trading prices of ONEOK Common Stock or EnLink Units.

At the time the Mergers are completed, EnLink unitholders will receive, for each EnLink Unit they own as of immediately prior to the First Merger Effective Time, 0.1412 shares of ONEOK Common Stock. The Exchange Ratio is fixed (subject to adjustments in accordance with the terms of the Merger Agreement), which means that it will not change between the date of this proxy statement/prospectus and the closing date, regardless of whether the market price of either ONEOK Common Stock or EnLink Units changes. Therefore, the value of the Merger Consideration will depend on the market price of ONEOK Common Stock at the First Merger Effective Time. The respective market prices of both ONEOK Common Stock and EnLink Units have fluctuated since the date of the announcement of the parties’ entry into the Merger Agreement and will continue to fluctuate from the date of this proxy statement/prospectus to the date of the EnLink Special Meeting, the closing date and thereafter. As of November 22, 2024, the last trading day prior to the announcement of the parties’ entry into the Merger Agreement, the closing price of ONEOK Common Stock was $117.05 and the market price of EnLink Units was $15.75. The market price of ONEOK Common Stock, when received by EnLink unitholders after the Mergers are completed, could be greater than, less than or the same as the market price of ONEOK Common Stock on the date of this proxy statement/prospectus or at the time of the EnLink Special Meeting. Accordingly, you should obtain current stock and unit price quotations, respectively, for ONEOK Common Stock and EnLink Units before deciding how to vote or abstain from voting on any of the proposals described in this proxy statement/prospectus.

Completion of the Mergers is subject to a number of conditions, including certain conditions that may not be satisfied or completed on a timely basis or at all.

Completion of the Mergers is subject to a number of conditions, which may be beyond the parties’ control and may prevent, delay or otherwise materially adversely affect the completion of the Mergers. These conditions include, among other things, EnLink unitholder approval of the Merger Agreement and the Mergers contemplated thereby. ONEOK and EnLink cannot predict with certainty whether and when any of these conditions will be satisfied. Any delay in completing the Mergers could cause ONEOK not to realize, or delay the realization, of some or all of the benefits that the companies expect to achieve from the Mergers. In such context, the date on which EnLink’s unitholders will receive the Merger Consideration is also uncertain. For additional information regarding the conditions to completion of the Mergers, please see the section entitled “The Merger Agreement — Conditions to the Completion of the Mergers.”

The Merger Agreement limits EnLink’s ability to pursue alternatives to the Mergers, which may discourage other companies from making a favorable alternative transaction proposal and, in specified circumstances, could require EnLink to pay ONEOK a termination fee.

The EnLink Board, based in part on the EnLink Conflicts Committee’s recommendation, has recommended that the EnLink unitholders vote in favor of the Merger Agreement and the Mergers. Under the Merger Agreement, if the EnLink Board or the EnLink Conflicts Committee, withdraws, modifies or qualifies, or proposes publicly to withdraw, modify or qualify its recommendation with respect to the Merger Proposal, unless the Merger Agreement has been terminated in accordance with its terms, EnLink will still be required to submit the Merger Proposal to a vote at the EnLink Special Meeting. For more information, please see the section entitled “The Merger Agreement — No Change of Recommendation by EnLink.” The Merger Agreement further provides that, if ONEOK terminates the Merger Agreement in response to an adverse recommendation change by the EnLink Conflicts Committee, EnLink will be required to pay ONEOK a termination payment of $143,978,000. In the event of termination of the Merger Agreement by ONEOK due to an uncured breach by EnLink or Manager, EnLink has agreed to reimburse ONEOK for all of its reasonable documented out-of-pocket expenses in connection with the Mergers, up to $10.0 million. In the event of termination of the Merger Agreement by EnLink due to an uncured breach by ONEOK or the Merger Subs, ONEOK has agreed to reimburse EnLink for all of its reasonable documented out-of-pocket expenses in connection with the Mergers, up to $10.0 million. Pease see the section entitled “The Merger Agreement — Termination Fee” for additional details.

These provisions regarding an EnLink adverse recommendation change could discourage a potential third-party acquirer or other strategic transaction partner that might have an interest in EnLink from considering or pursuing an alternative transaction with EnLink. These provisions might also result in a potential third-party acquirer or other strategic transaction partner proposing to pay a lower price than it might otherwise have proposed to pay because of the added expense of the termination fee that may become payable in certain circumstances.

ONEOK or EnLink may waive or modify the Merger Agreement, including one or more of the closing conditions, without re-soliciting unitholder approval or without consent of the ONEOK shareholders.

ONEOK or EnLink may determine to waive, in whole or part, one or more of the conditions to closing the Mergers prior to ONEOK or EnLink, as the case may be, being obligated to consummate the Mergers. Each of ONEOK and EnLink currently expects to evaluate the materiality of any waiver and its effect on its respective shareholders or unitholders in light of the facts and circumstances at the time, to determine whether any amendment of this proxy statement/prospectus or any re-solicitation of proxies of the EnLink unitholders is required in light of such waiver. Any determination whether to waive any condition to the Mergers or to re-solicit EnLink unitholder approval or amending or supplementing this proxy statement/prospectus as a result of a waiver will be made by ONEOK or EnLink at the time of such waiver based on the facts and circumstances as they exist at that time. Additionally, prior to the consummation of the Mergers, the parties to the Merger Agreement or other related transaction document may agree to modify or waive the terms or conditions of such documents without consent from the EnLink unitholders or the ONEOK shareholders.

The market price for ONEOK Common Stock following the closing may be affected by factors different from those that historically have affected or currently affect ONEOK Common Stock and EnLink Units.

Upon completion of the Mergers, EnLink unitholders who receive ONEOK Common Stock will become shareholders of ONEOK. ONEOK’s financial position may differ from its financial position before the completion of the Mergers, and the results of operations of ONEOK following the Mergers may be affected by some factors that are different from those currently affecting the results of operations of ONEOK and those currently affecting the results of operations of EnLink. Accordingly, the market price and performance of ONEOK Common Stock is likely to be different from the performance of EnLink Units, or ONEOK Common Stock in the absence of the Mergers. In addition, general fluctuations in stock markets could have a material adverse effect on the market for, or liquidity of, ONEOK Common Stock, regardless of ONEOK’s actual operating performance. For a discussion of the businesses of ONEOK and EnLink, and important factors to consider in connection with those businesses, see the documents attached hereto or incorporated by reference and referred to in “Where You Can Find More Information.”

Following the Mergers, current ONEOK shareholders and current EnLink unitholders will have reduced ownership and voting interest in ONEOK and will exercise less influence over ONEOK’s management.

As of the date of this proxy statement/prospectus, based on the Exchange Ratio, the number of outstanding EnLink Units and the number of outstanding shares of ONEOK Common Stock, it is expected that immediately following the First Merger Effective Time, current EnLink unitholders would own approximately 5.9% of the issued and outstanding shares of ONEOK Common Stock and current ONEOK shareholders would own approximately 94.1% of the issued and outstanding shares of ONEOK Common Stock, in each case on a fully diluted basis. As a result, ONEOK’s current shareholders and EnLink’s current unitholders will have less influence on the policies of ONEOK following the Mergers than they currently have on the policies of ONEOK and EnLink, respectively.

ONEOK Common Stock to be received by EnLink unitholders as a result of the Mergers will have different rights from EnLink Units.

Following completion of the Mergers, EnLink unitholders will no longer hold EnLink Units but will instead be shareholders of ONEOK. There are important differences between the rights of EnLink unitholders and the rights of ONEOK shareholders. For a discussion of the different rights associated with EnLink Units and ONEOK Common Stock, please see the section entitled “Comparison of Rights of EnLink Unitholders and ONEOK Shareholders.”

Completion of the Mergers may trigger change in control or other provisions in certain agreements to which EnLink or any of its subsidiaries or joint ventures is a party.

The completion of the Mergers may trigger change in control or other provisions in certain agreements to which EnLink or any of its subsidiaries or joint ventures is a party. If EnLink is unable to negotiate waivers of those provisions, the counterparties may exercise their rights and remedies under such agreements, potentially terminate such agreements, or seek monetary damages. Even if EnLink is able to negotiate waivers, the counterparties may require a fee for such waivers or seek to renegotiate such agreements on terms less favorable to EnLink or the applicable subsidiary or joint venture. Further, it may not be practicable to obtain waivers for certain change of control provisions and the conditions to such provisions may be subject to factors beyond ONEOK’s control. For example, the Mergers will constitute a change of control under the indentures governing EnLink’s 5.625% Senior Notes due 2028 and 6.500% Senior Notes due 2030 and, if such change of control were to be accompanied by certain ratings events, EnLink would be required to offer to repurchase such notes at a price set forth in the applicable indenture.

ONEOK and EnLink are expected to incur significant transaction costs in connection with the Mergers, which may be in excess of those anticipated by them.

ONEOK and EnLink have incurred and are expected to continue to incur a number of non-recurring costs associated with negotiating and completing the Mergers, combining the operations of the two companies and achieving desired synergies. These costs have been, and will continue to be, substantial and, in many cases, will be borne by ONEOK and EnLink whether or not the Mergers are completed. A substantial majority of non-recurring expenses will consist of transaction costs and include, among others, fees paid to financial, legal, accounting and other advisors, employee retention, severance and benefit costs, and filing fees. ONEOK will also incur costs related to formulating and implementing integration plans, including facilities and systems consolidation costs and other employment-related costs. ONEOK and EnLink will continue to assess the magnitude of these costs, and additional unanticipated costs may be incurred in connection with the Mergers and the integration of the two companies’ businesses. While ONEOK and EnLink have assumed that a certain level of expenses would be incurred, there are many factors beyond their control that could affect the total amount or the timing of the expenses. The elimination of duplicative costs, as well as the realization of other efficiencies related to the integration of the businesses, may not offset integration-related costs and achieve a net benefit in the near term, or at all. The costs described above and any unanticipated costs and expenses, many of which will be borne by ONEOK or EnLink even if the Mergers are not completed, could have an adverse effect on ONEOK’s or EnLink’s financial condition and operating results.

If the Merger Agreement is terminated, under certain circumstances, EnLink may be obligated to pay a termination fee to ONEOK. This fee could require EnLink to seek loans or use its available cash that would have otherwise been available for operations, dividends or other general corporate purposes.

Upon termination of the Merger Agreement under certain circumstances, EnLink may be required to pay ONEOK a termination fee equal to $143,978,000 or to reimburse ONEOK’s expenses up to $10.0 million, and ONEOK may be required to reimburse EnLink’s expenses up to $10.0 million. If the Merger Agreement is terminated, the termination fee or reimbursement of expenses required to be paid, if any, by EnLink under the Merger Agreement may require EnLink to seek loans or borrow amounts to enable it to pay the fee to ONEOK. Payment of these amounts would reduce the cash EnLink has available for operations, distributions or other general corporate purposes. Please see the sections entitled “The Merger Agreement — Payment of Expenses” and “The Merger Agreement — Termination Fee.”

ONEOK may be unable to integrate the businesses of ONEOK and EnLink successfully or realize the anticipated benefits of the Mergers, which may adversely affect the value of the ONEOK Common Stock that EnLink unitholders would receive in the Mergers.

ONEOK’s ability to achieve the anticipated benefits of the Mergers will depend in part upon whether ONEOK can integrate EnLink’s business into its existing business in an efficient and effective manner. ONEOK may not be able to accomplish the integration process successfully. Potential difficulties that may be encountered as part of the integration process include the following:

•        the inability to successfully combine EnLink’s business into ONEOK’s existing business in a manner that permits it to achieve, on a timely basis, or at all, the enhanced revenue opportunities and cost savings and other benefits anticipated to result from the Mergers;

•        complexities associated with managing the combined business, including difficulty addressing possible differences in operational philosophies and the challenge of integrating complex systems, technology, networks and other assets of each of the companies in a seamless manner that minimizes any adverse impact on customers, suppliers, employees and other constituencies;

•        the assumption of contractual obligations with less favorable or more restrictive terms; and

•        potential unknown liabilities and unforeseen increased expenses or delays associated with the Mergers.

In addition, ONEOK and EnLink have operated and, until the completion of the Mergers, will continue to operate, independently. It is possible that the integration process could result in the disruption of, or the loss of momentum in, each company’s ongoing businesses or inconsistencies in standards, controls, procedures and policies.

Any of these issues could adversely affect each company’s ability to maintain relationships with customers, suppliers, employees and other constituencies or achieve the anticipated benefits of the Mergers or could reduce each company’s earnings or otherwise adversely affect ONEOK’s business and financial results following the Mergers, including the value of the ONEOK Common Stock that EnLink unitholders will receive as Merger Consideration.

The Merger Agreement subjects ONEOK and EnLink to restrictions on their respective business activities prior to the First Merger Effective Time.

The Merger Agreement subjects ONEOK and EnLink to restrictions on their respective business activities prior to the First Merger Effective Time. The Merger Agreement obligates EnLink to conduct its business (i) in the ordinary course of business consistent with past practice and (ii) in compliance with the EnLink Midstream Interim Period Restricted Actions, dated as of October 15, 2024 (as may be amended or supplemented, or as any actions thereunder may be waived or approved by the applicable representative of ONEOK, from time to time, the “EnLink Midstream Interim Period Restricted Actions”). The Merger Agreement restricts EnLink’s ability to (i) declare additional dividends (subject to certain exceptions), (ii) adopt a plan of liquidation, dissolution or restructuring, (iii) fail to consistently maintain material rights-of-way and real property, (iv) split or otherwise recapitalize EnLink Units or effect any other similar transaction, or (v) agree, in writing or otherwise, to take any of the foregoing actions or any action that would reasonably be expected to prevent or delay the ability of the parties to satisfy any of the conditions to or the consummation of the Mergers. The EnLink Midstream Interim Period Restricted Actions restricts EnLink’s ability to take certain actions, including, among other things, (i) make capital expenditures,

(ii) create or incur indebtedness, (iii) merge or consolidate with other businesses, and (iv) enter into or amend rights under material contracts. These restrictions could prevent EnLink from pursuing certain business opportunities that arise prior to the First Merger Effective Time and are outside the ordinary course of business. The Merger Agreement also restricts ONEOK’s ability to (i) amend its organizational documents in a way that would prevent the consummation of the Mergers, (ii) declare additional dividends (subject to certain exceptions), (iii) split or otherwise recapitalize ONEOK Common Stock or effect any other similar transaction, (iv) adopt a plan of liquidation, dissolution or restructuring, (v) directly or indirectly purchase or acquire any additional EnLink Units, or (vi) agree, in writing or otherwise, to take any of the foregoing actions or any action that would reasonably be expected to prevent or delay the ability of the parties to satisfy any of the conditions to or the consummation of the Mergers. Please see the section entitled “The Merger Agreement — Covenants — Conduct of Business Pending the Mergers” for additional details.

Uncertainties associated with the Mergers may cause a loss of management personnel and other key employees of ONEOK and EnLink, which could adversely affect the future business and operations of ONEOK following the Mergers.

ONEOK and EnLink are dependent on the experience and industry knowledge of their respective officers and other key employees to execute their business plans. ONEOK’s success after the Mergers will depend in part upon its ability to retain key management personnel and other key employees of both ONEOK and EnLink. Current and prospective employees of ONEOK and EnLink may experience uncertainty about their roles within ONEOK following the Mergers or other concerns regarding the timing and completion of the Mergers or the operations of ONEOK following the Mergers, any of which may have an adverse effect on the ability of ONEOK and EnLink to retain or attract key management and other key personnel. If ONEOK and EnLink are unable to retain personnel, including key management, who are critical to the future operations of the companies, ONEOK and EnLink could face disruptions in their operations, loss of existing customers, loss of key information, expertise or know-how and unanticipated additional recruitment and training costs. In addition, the loss of key personnel could diminish the anticipated benefits of the Mergers. No assurance can be given that ONEOK, following the Mergers, will be able to retain or attract key management personnel and other key employees to the same extent that ONEOK and EnLink have previously been able to retain or attract their own employees.

The Mergers may not be completed and the Merger Agreement may be terminated in accordance with its terms. Failure to complete the Mergers could negatively impact the price of ONEOK Common Stock and EnLink Units and have a material adverse effect on their results of operations, cash flows and financial position.

ONEOK or EnLink may elect to terminate the Merger Agreement in accordance with its terms in certain circumstances, as further detailed in the section entitled “The Merger Agreement — Termination of the Merger Agreement.” If the Mergers are not completed for any reason, including as a result of the EnLink unitholders’ failure to approve the Merger Proposal, the ongoing businesses of ONEOK and EnLink may be materially adversely affected and, without realizing any of the benefits of having completed the Mergers, ONEOK and EnLink would be subject to a number of risks, including the following:

•        ONEOK and EnLink may experience negative reactions from the financial markets, including negative impacts on their respective stock and unit prices;

•        ONEOK and EnLink and their respective subsidiaries may experience negative reactions from their respective customers, suppliers, vendors, landlords, joint venture partners and other business partners;

•        ONEOK and EnLink will still be required to pay certain significant costs relating to the Mergers, such as legal, accounting, financial advisor and printing fees;

•        matters relating to the Mergers (including integration planning) require substantial commitments of time and resources by each company’s management, which may have resulted in the distraction of each company’s management from ongoing business operations and pursuing other opportunities that could have been beneficial to the companies; and

•        litigation related to any failure to complete the Mergers or related to any enforcement proceeding commenced against ONEOK or EnLink to perform their respective obligations pursuant to the Merger Agreement.

If the Mergers are not completed, the risks described above may materialize and they may have a material adverse effect on ONEOK’s or EnLink’s results of operations, cash flows, financial position and stock prices. In addition to the above risks, if the Merger Agreement is terminated or the Mergers are otherwise not completed for any reason, there can be no assurances that either ONEOK or EnLink will be able to find a party willing to enter into an alternative transaction as attractive as the Mergers.

EnLink’s directors and executive officers have interests in the Mergers that may be different from, or in addition to, the interests of the EnLink unitholders generally.

In considering the recommendations of the EnLink Conflicts Committee and the EnLink Board that EnLink unitholders vote in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal, EnLink unitholders should be aware of and take into account the fact that, aside from their interests as EnLink unitholders, certain of EnLink’s directors and executive officers have interests in the Mergers that may be different from, or in addition to, the interests of EnLink unitholders generally. These interests include, among others, rights to continuing indemnification and directors’ and officers’ liability insurance. For a more detailed description of these interests, please see the section entitled “The Mergers — Interests of Certain EnLink Directors and Executive Officers in the Mergers.” The EnLink Conflicts Committee and the EnLink Board were aware of and considered these potential interests, among other matters, in evaluating and negotiating the Merger Agreement and the transactions contemplated therein, in approving the Mergers and in recommending that EnLink unitholders approve the Merger Proposal and the Non-Binding Advisory Compensation Proposal.

Litigation relating to the Mergers could result in an injunction preventing completion of the Mergers, substantial costs to ONEOK and EnLink and/or may adversely affect ONEOK’s business, financial condition or results of operations following the Mergers.

Securities class action lawsuits and derivative lawsuits are often brought against public companies that have entered into acquisition, merger or other business combination agreements. Even if such a lawsuit is without merit, defending against these claims can result in substantial costs and divert management time and resources. An adverse judgment could result in monetary damages, which could have a negative impact on ONEOK’s and EnLink’s respective liquidity and financial condition.

Lawsuits that may be brought against ONEOK, EnLink or their respective directors could also seek, among other things, injunctive relief or other equitable relief, including a request to rescind parts of the Merger Agreement already implemented and to otherwise enjoin the parties from consummating the Mergers. One of the conditions to the closing of the Mergers is that no injunction by any court or other tribunal of competent jurisdiction has been entered and continues to be in effect and no law has been adopted or is effective, in either case that prohibits or makes illegal the closing of the Mergers. Consequently, if a plaintiff is successful in obtaining an injunction prohibiting completion of the Mergers, that injunction may delay or prevent the Mergers from being completed within the expected timeframe or at all, which may adversely affect ONEOK’s and EnLink’s respective business, financial position and results of operation.

There can be no assurance that any of the defendants will be successful in the outcome of any pending or any potential future lawsuits. The defense or settlement of any lawsuit or claim that remains unresolved at the time the Mergers are completed may adversely affect ONEOK’s and EnLink’s business, financial condition, results of operations and cash flows.

EnLink unitholders will not be entitled to appraisal rights in the Mergers.

Appraisal rights are statutory rights that enable security holders to dissent from certain extraordinary transactions, such as certain mergers, and to demand that the company pay the fair value for their securities as determined by a court in a judicial proceeding instead of receiving the consideration offered to security holders in connection with the applicable transaction. Under the DLLCA and the EnLink Operating Agreement, EnLink unitholders do not have appraisal rights in connection with the Mergers, as more fully described in “The Mergers — No Appraisal Rights.”

Declaration, payment and amounts of dividends, if any, distributed to ONEOK shareholders following the Mergers will be uncertain.

Although ONEOK has paid cash dividends on ONEOK Common Stock in the past, ONEOK may determine not to declare dividends in the future or may reduce the amount of dividends paid in the future. Any payment of future dividends will be at the discretion of the ONEOK Board and will depend on ONEOK’s results of operations, financial condition, cash requirements, future prospects and other considerations that the ONEOK Board deems relevant, including, but not limited to:

•        ONEOK may not have enough cash to pay such dividends or to repurchase shares due to its cash requirements, capital spending plans, cash flow or financial position;

•        decisions on whether, when and in which amounts to make any future distributions will remain at all times entirely at the discretion of the ONEOK Board, which could change its dividend practices at any time and for any reason;

•        ONEOK’s desire to maintain or improve the credit ratings on its debt;

•        the amount of dividends that ONEOK may distribute to its shareholders is subject to restrictions under Oklahoma law; and

•        the agreements governing ONEOK’s indebtedness.

Shareholders should be aware that they have no contractual or other legal right to dividends that have not been declared.

The trading price and volume of ONEOK Common Stock may be volatile following the Mergers.

The trading price and volume of ONEOK Common Stock may be volatile following completion of the Mergers. The stock markets in general have experienced extreme volatility that has often been unrelated to the operating performance of particular companies. These broad market fluctuations may adversely affect the trading price of ONEOK Common Stock. As a result, ONEOK shareholders and EnLink unitholders who receive ONEOK Common Stock may suffer a loss on their investment. Many factors may impair the market for ONEOK Common Stock and the ability of investors to sell shares at an attractive price and could also cause the market price and demand for ONEOK Common Stock to fluctuate substantially, which may negatively affect the price and liquidity of ONEOK Common Stock. Many of these factors and conditions are beyond the control of ONEOK or its shareholders.

Following the consummation of the Mergers, the market price of ONEOK Common Stock may be depressed by the perception that former EnLink unitholders may sell the shares of ONEOK Common Stock they will acquire at closing and for other reasons related to the Mergers.

Subject to applicable securities laws, former EnLink unitholders may seek to sell shares of ONEOK Common Stock held by them immediately following the consummation of the Mergers. The Merger Agreement contains no restriction on their ability to sell such shares of ONEOK Common Stock. These sales (or the perception that these sales may occur), coupled with the increase in the outstanding number of shares of ONEOK Common Stock, may affect the market for, and the market price of, shares of ONEOK Common Stock in an adverse manner.

The financial forecasts are based on various assumptions that may not be realized.

The financial estimates set forth in the forecasts included under the section entitled “The Mergers — Certain Unaudited Forecasted Financial Information of EnLink” were based on assumptions of, and information available to, EnLink management when prepared, and these estimates and assumptions are subject to uncertainties, many of which are beyond ONEOK’s and EnLink’s control and may not be realized. Many factors mentioned in this proxy statement/prospectus, including the risks outlined in this “Risk Factors” section and the events or circumstances described under “Cautionary Statement Regarding Forward-Looking Statements,” will be important in determining ONEOK’s future results. As a result of these contingencies, actual future results may vary materially from EnLink’s

estimates. In view of these uncertainties, the inclusion of financial estimates in this proxy statement/prospectus is not and should not be viewed as a representation that the forecasted results will necessarily reflect actual future results.

EnLink’s financial estimates were not prepared with a view toward public disclosure, and such financial estimates were not prepared with a view toward compliance with published guidelines of any regulatory or professional body. Further, any forward-looking statement speaks only as of the date on which it is made, and neither ONEOK nor EnLink undertakes any obligation, other than as required by applicable law, to update the financial estimates herein to reflect events or circumstances after the date those financial estimates were prepared or to reflect the occurrence of anticipated or unanticipated events or circumstances.

The prospective financial information included in this document has been prepared by, and is the responsibility of, EnLink’s management. Neither KPMG LLP nor PricewaterhouseCoopers LLP has not audited, reviewed, examined, compiled nor applied agreed-upon procedures with respect to the accompanying prospective financial information and, accordingly, neither KPMG LLP nor PricewaterhouseCoopers LLP express an opinion or any other form of assurance with respect thereto. The report of KPMG LLP contained in EnLink’s Annual Report on Form 10-K for the year ended December 31, 2023, which is incorporated by reference into this proxy statement/prospectus, relates to historical financial information of EnLink, and such report does not extend to the Forecasted Financial Information and should not be read to do so. In addition, the PricewaterhouseCoopers LLP report incorporated by reference in this document relates to ONEOK’s previously issued financial statements. It does not extend to the prospective financial information and should not be read to do so. For more information, please see the section entitled “The Mergers — Certain Unaudited Forecasted Financial Information of EnLink.”

The opinion of Evercore, the financial advisor to the EnLink Conflicts Committee, speaks only as of the date rendered based on circumstances and conditions existing as of the signing of the Merger Agreement and will not reflect changes in circumstances between the signing of the Merger Agreement and the completion of the Mergers.

The EnLink Conflicts Committee has received an opinion from its financial advisor, Evercore, in connection with the signing of the Merger Agreement based on circumstances and conditions existing at that time but has not obtained any updated opinion from its financial advisor as of the date of this proxy statement/prospectus. Changes in the operations and prospects of ONEOK or EnLink, general market and economic conditions and other factors that may be beyond the control of ONEOK or EnLink, and on which the EnLink Conflicts Committee’s financial advisor’s opinion was based, may significantly alter the value of ONEOK or EnLink or the prices of the shares of ONEOK Common Stock or EnLink Units by the time the Mergers are completed. The opinion does not speak as of the time the Mergers will be completed or as of any date other than the date of the opinion. Because the EnLink Conflicts Committee currently does not anticipate asking its financial advisor to update its opinion, the opinion will not address the fairness of the Merger Consideration from a financial point of view at the time the Mergers are completed. The EnLink Conflicts Committee’s recommendation that EnLink unitholders vote in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal, however, is made as of the date of this proxy statement/prospectus.

The synergies attributable to the Mergers may vary from expectations.

ONEOK may fail to realize the anticipated benefits and synergies expected from the Mergers, which could adversely affect its business, financial condition and operating results. The success of the Mergers will depend, in significant part, on ONEOK’s ability to successfully integrate EnLink’s business, grow its revenue and realize the anticipated strategic benefits and synergies from the Mergers. ONEOK believes that the Mergers will provide operational and financial scale, increasing free cash flow, and enhancing its corporate rate of return. However, achieving these goals requires, among other things, realization of the targeted cost and commercial synergies expected from the Mergers. This growth and the anticipated benefits of the Mergers may not be realized fully or at all or may take longer to realize than expected. Actual operating, technological, strategic and revenue opportunities, if achieved at all, may be less significant than expected or may take longer to achieve than anticipated. If ONEOK is not able to achieve these objectives and realize the anticipated benefits and synergies expected from the Mergers within the anticipated timing or at all, ONEOK’s business, financial condition and operating results may be adversely affected, its earnings per share may be diluted, the accretive effect of the Mergers may decrease or be delayed and its share price may be negatively impacted.

The future results of ONEOK following the Mergers will suffer if it does not effectively manage its expanded operations.

Following the Mergers, the size of the business of ONEOK will increase. ONEOK’s future success will depend, in part, upon its ability to manage this expanded business, which may pose challenges for management, including challenges related to the management and monitoring of new operations and associated increased costs and complexity. ONEOK may also face increased scrutiny from governmental authorities as a result of the increase in the size of its business. There can be no assurances that ONEOK will be successful or that it will realize the expected operating efficiencies, cost savings, revenue enhancements or other benefits currently anticipated from the Mergers.

The pendency of the Mergers and/or the completion of the Mergers may result in a loss of customers, suppliers, vendors, landlords, joint venture partners and other business partners and may result in the termination of existing contracts.

In connection with the pending Mergers, some of the customers, suppliers, vendors, landlords, joint venture partners and other business partners of each of ONEOK and EnLink may delay or defer decisions, which could adversely affect the revenues, earnings, funds from operations, cash flows and expenses of ONEOK and EnLink, regardless of whether the Mergers are completed, and of the combined company, if the Mergers are completed.

Following the Mergers, some of the customers, suppliers, vendors, landlords, joint venture partners and other business partners of ONEOK or EnLink may terminate or scale back their current or prospective business relationships with ONEOK. Some customers may not wish to source a larger percentage of their needs from a single company or may feel that ONEOK is too closely allied with one of their competitors. In addition, EnLink has contracts with customers, suppliers, vendors, landlords, joint venture partners and other business partners that may require EnLink to obtain consents from these other parties in connection with the Mergers, which may not be obtained on favorable terms or at all. If relationships with customers, suppliers, vendors, landlords, joint venture partners and other business partners are adversely affected by the Mergers, or if ONEOK, following the Mergers, loses the benefits of the contracts of EnLink, ONEOK’s business and financial performance could suffer.

ONEOK shareholders may experience dilution in the future.

The percentage ownership of ONEOK shareholders may be diluted in the future because of equity issuances for acquisitions, capital market transactions or otherwise, including, without limitation, equity awards that ONEOK may grant to its directors, officers and employees and pursuant to ONEOK “at-the-market” offerings of ONEOK Common Stock. Such issuances may have a dilutive effect on ONEOK’s earnings per share, which could adversely affect the market price of ONEOK Common Stock.

Certain employees of EnLink will have rights to purchase or receive shares of ONEOK Common Stock after the Mergers as a result of the conversion of their EnLink equity awards into ONEOK equity awards. The conversion of these EnLink equity awards into ONEOK equity awards is described in further detail in the section entitled “The Merger Agreement — Treatment of EnLink Equity Awards.” The issuance of shares of ONEOK Common Stock pursuant to these awards will dilute the percentage ownership of ONEOK shareholders. It is also expected that, from time to time after the closing of the Mergers, the Executive Compensation Committee of the ONEOK Board will grant additional equity awards to employees and directors under ONEOK’s compensation and employee benefit plans. These additional equity awards will have a dilutive effect on ONEOK’s earnings per share, which could adversely affect the market price of ONEOK Common Stock.

Further, pursuant to ONEOK’s “at-the-market” equity program, it can, but is under no obligation to, offer and sell ONEOK Common Stock up to an aggregate offering price of $1.0 billion. The program allows ONEOK to offer and sell ONEOK Common Stock at prices it deems appropriate through a sales agent, in forward sales transactions through a forward seller or directly to one or more of the program’s managers acting as principals. Sales of ONEOK Common Stock may be made by means of ordinary brokers’ transactions on the NYSE, in block transactions or as otherwise agreed to between ONEOK and the sales agent. As of September 30, 2024, no sales have been made under ONEOK’s “at-the-market” program.

In addition, the Amended and Restated Certificate of Incorporation of ONEOK, as amended (the “ONEOK Charter”), authorizes ONEOK to issue, without the approval of ONEOK shareholders, one or more classes or series of preferred stock having such designations, powers, preferences and relative, participating, optional and other special rights, including preferences over ONEOK Common Stock with respect to dividends and distributions, as the ONEOK Board generally may determine. The terms of one or more classes or series of preferred stock could dilute the voting power or reduce the value of ONEOK Common Stock. For example, the repurchase or redemption rights or liquidation preferences that could be assigned to holders of preferred stock could affect the residual value of ONEOK Common Stock. For more information, please see the section entitled “Comparison of Rights of EnLink Unitholders and ONEOK Shareholders.”

ONEOK has a significant amount of indebtedness, which will limit its liquidity and financial flexibility, and any downgrade of its credit rating could adversely impact ONEOK. ONEOK may also incur additional indebtedness in the future.

As of September 30, 2024, ONEOK and EnLink had total indebtedness of approximately $28.1 billion and $4.9 billion, respectively. Accordingly, ONEOK will have substantial indebtedness following completion of the Mergers. In addition, subject to the limits contained in the documents governing such indebtedness, ONEOK may be able to incur substantial additional debt from time to time to finance working capital, capital expenditures, investments or acquisitions or for other purposes. ONEOK’s indebtedness and other financial commitments have important consequences to its business, including, but not limited to:

•        making it more difficult for ONEOK to satisfy its obligations with respect to senior notes and other indebtedness due to the increased debt-service obligations, which could, in turn, result in an event of default on such other indebtedness or the senior notes;

•        requiring ONEOK to dedicate a substantial portion of its cash flows from operations to debt service payments, thereby limiting its ability to fund working capital, capital expenditures, investments or acquisitions and other general corporate purposes;

•        increasing ONEOK’s vulnerability to general adverse economic and industry conditions, including low commodity price environments;

•        limiting ONEOK’s ability to obtain additional financing due to higher costs and more restrictive covenants;

•        limiting ONEOK’s flexibility in planning for, or reacting to, changes in its business and the industry in which it operates; and

•        placing ONEOK at a competitive disadvantage compared with its competitors that have proportionately less debt and fewer guarantee obligations.

In addition, ONEOK and EnLink receive credit ratings from rating agencies in the U.S. with respect to their indebtedness. Any credit downgrades resulting from the Mergers or otherwise could adversely impact ONEOK’s ability to access financing and trade credit, require ONEOK to offer to repurchase certain of EnLink’s outstanding senior notes, require ONEOK to provide additional letters of credit or other assurances under contractual arrangements and increase ONEOK’s interest rate under any credit facility borrowing as well as the cost of any other future debt.

Other Risk Factors Relating to ONEOK and EnLink

As a result of entering into the Merger Agreement, ONEOK’s and EnLink’s businesses are and will be subject to the risks described above. In addition, ONEOK and EnLink are, and following completion of the Mergers, ONEOK will be, subject to the risks described in ONEOK’s and EnLink’s most recent Annual Report on Form 10-K (as amended) as updated by subsequent Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, which are filed with the SEC and incorporated by reference into this proxy statement/prospectus. Please see the section entitled “Where You Can Find More Information” for the location of information incorporated by reference into this proxy statement/prospectus.

Tax Risks Related to the Mergers and the Ownership of ONEOK Common Stock Received in the Mergers

In addition to reading the following risk factors, you are strongly urged to read “Material U.S. Federal Income Tax Consequences” for a more complete discussion of the expected U.S. federal income tax consequences of the Mergers and owning and disposing of shares of ONEOK Common Stock received in the Mergers.

There could be limitations on the utilization of the historic U.S. net operating loss carryforwards of EnLink.

ONEOK’s ability to utilize EnLink’s historic U.S. net operating loss carryforwards to reduce future taxable income following the consummation of the Mergers is expected to be subject to various limitations under the Code.

In general, Section 382 of the Code imposes such a limitation upon the occurrence of ownership changes resulting from issuances of a company’s stock or the sale or exchange of such company’s stock by certain shareholders if, as a result, there is an aggregate change of more than 50% in the beneficial ownership of such company’s stock by such shareholders during any three-year period. The limitation (a “Section 382 limitation”) with respect to the loss carryforwards of a company that has undergone such an ownership change generally is equal to (i) the fair market value of such company’s equity multiplied by (ii) a percentage approximately equivalent to the yield on long-term tax-exempt bonds during the month in which the ownership change occurs. In addition, the Section 382 limitation is increased if there are recognized built-in gains during the five-year post-change period, but only to the extent of any net unrealized built-in gain existing on the date of the ownership change. If a corporation that is already subject to a Section 382 limitation as a result of an ownership change undergoes a second ownership change, net operating losses attributable to the period preceding the earlier ownership change are treated as pre-change losses with respect to both ownership changes. The second ownership change may result in a lesser, but never a greater, Section 382 limitation following such ownership change.

ONEOK and EnLink believe that the transactions in connection with the Mergers, if consummated, will result in an ownership change under Section 382 of the Code with respect to EnLink. As a result, ONEOK could be subject to the Section 382 limitation with respect to EnLink’s loss carryforwards that exist on the date of the Mergers.

For a more complete discussion of the U.S. federal income tax consequences of the Mergers, see the section entitled “Material U.S. Federal Income Tax Consequences.”

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

Certain statements and information in this document may constitute “forward-looking statements” within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act. All statements, other than statements of historical fact, included in this document that address activities, events or developments that ONEOK or EnLink expects, believes or anticipates will or may occur in the future are forward-looking statements. Words such as “estimate,” “project,” “predict,” “believe,” “expect,” “anticipate,” “potential,” “opportunity,” “create,” “intend,” “could,” “would,” “may,” “plan,” “will,” “guidance,” “look,” “goal,” “target,” “future,” “build,” “focus,” “continue,” “strive,” “allow” or the negative of such terms or other variations thereof and words and terms of similar substance used in connection with any discussion of future plans, actions, or events identify forward-looking statements. However, the absence of these words does not mean that the statements are not forward-looking. These forward-looking statements include, but are not limited to, statements regarding the Mergers, the expected closing of the Mergers and the timing thereof, and descriptions of ONEOK following the consummation of the Mergers and its operations, strategies and plans, integration, debt levels and leverage ratio, capital expenditures, cash flows and anticipated uses thereof, synergies, opportunities and anticipated future performance, including maintaining current ONEOK management, enhancements to investment-grade credit profile, an expected accretion to earnings and free cash flow, dividend payments and potential share repurchases, increase in value of tax attributes and expected impact on EBITDA after giving effect to the Mergers. Information adjusted for the Mergers should not be considered a forecast of future results. There are a number of risks and uncertainties that could cause actual results to differ materially from the forward-looking statements included in this proxy statement/prospectus. These include the risk that ONEOK will not be able to successfully integrate EnLink’s business; the risk that cost savings, synergies and growth from the Mergers may not be fully realized or may take longer to realize than expected; the risk that the credit ratings following the Mergers may be different from what the companies expect; the risk that a condition to closing of the Mergers may not be satisfied, that a party may terminate the Merger Agreement or that the closing of the Mergers might be delayed or not occur at all; the possibility that the EnLink unitholders may not approve the Merger Proposal; the risk of potential adverse reactions or changes to business or employee relationships, including those resulting from the announcement or completion of the Mergers; risks related to the occurrence of any other event, change or circumstance that could give rise to the termination of the Merger Agreement; the risk that changes in ONEOK’s capital structure could have adverse effects on the market value of its securities; risks related to the ability of ONEOK and EnLink to retain customers and retain and hire key personnel and maintain relationships with their suppliers and customers and on ONEOK’s and EnLink’s operating results and business generally; the risk that the Mergers could distract ONEOK’s and EnLink’s respective management teams from ongoing business operations or cause ONEOK and/or EnLink to incur substantial costs; the risk of any litigation relating to the Mergers; risks related to the impact of any economic downturn and any substantial decline in commodity prices; the risk of changes in governmental regulations or enforcement practices, especially with respect to environmental, health and safety matters; and other important factors that could cause actual results to differ materially from those projected. All such factors are difficult to predict and are beyond ONEOK’s or EnLink’s control, including those detailed in ONEOK’s Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K that are available on ONEOK’s website at www.oneok.com and on the website of the SEC at www.sec.gov, and those detailed in EnLink’s Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K that are available on EnLink’s website at www.enlink.com and on the website of the SEC. All forward-looking statements are based on assumptions that ONEOK and EnLink believe to be reasonable but that may not prove to be accurate. Any forward-looking statement speaks only as of the date on which such statement is made, and neither ONEOK nor EnLink undertakes any obligation to correct or update any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by applicable law. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof.

PARTIES TO THE MERGERS

ONEOK, Inc.

100 West Fifth Street
Tulsa, Oklahoma 74103
(918) 588-7000

ONEOK is an Oklahoma corporation, and its common stock is listed on the NYSE under the ticker symbol “OKE.” ONEOK delivers energy products and services vital to an advancing world. ONEOK is a leading midstream service provider of gathering, processing, fractionation, transportation, storage and marine exports. As one of the largest diversified energy infrastructure companies in North America, ONEOK delivers energy that makes a difference in the lives of people in the U.S. and around the world. Through its more than 50,000-mile pipeline network, ONEOK transports natural gas, NGLs, the output from crude oil refineries, including products such as gasoline, diesel fuel, aviation fuel, kerosene and heating oil and crude oil that help meet domestic and international energy demand, contribute to energy security and provide safe, reliable and responsible energy solutions needed today and into the future.

On October 15, 2024, pursuant to the GIP Interest Purchase Agreement, ONEOK acquired 200,340,753 EnLink Units, representing approximately 43.8% of the EnLink Units outstanding as of the Record Date. Pursuant to the terms of the Support Agreement, ONEOK has irrevocably agreed to vote such EnLink Units in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal. For additional information regarding the GIP Interest Acquisition and the Support Agreement, please see the sections entitled “The Mergers — Background of the Mergers” and “The Mergers — Support Agreement.”

Additional information about ONEOK and its subsidiaries, including, but not limited to, information regarding its business, properties, legal proceedings, financial statements, financial condition and results of operations, market risk, executive compensation and related party transactions is set forth in ONEOK’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023, and ONEOK’s Quarterly Reports on Form 10-Q for the quarters ended March 31, 2024, June 30, 2024 and September 30, 2024, which are each incorporated by reference into this document.

For more information about ONEOK, please visit ONEOK’s website at www.oneok.com. The information contained on ONEOK’s website or accessible through it does not constitute a part of this document.

EnLink Midstream, LLC

1722 Routh Street, Suite 1300
Dallas, Texas 75201
(214) 953-9500

EnLink is a publicly traded Delaware limited liability company formed in October 2013. Its assets consist of all of the outstanding common units of ENLK and all of the membership interests of ENLK GP. All of EnLink’s midstream energy assets are owned and operated by ENLK and its subsidiaries. EnLink primarily focuses on owning, operating, investing in, and developing midstream energy infrastructure assets to provide midstream energy services, including (i) gathering, compressing, treating, processing, transporting, storing, and selling natural gas; (ii) fractionating, transporting, storing, and selling NGLs; and (iii) gathering, transporting, storing, trans-loading, and selling crude oil and condensate. EnLink Units are listed on the NYSE under the ticker symbol “ENLC.”

Additional information about EnLink and its subsidiaries, including, but not limited to, information regarding its business, properties, legal proceedings, financial statements, financial condition and results of operations, executive compensation and related party transactions is set forth in EnLink’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023 and EnLink’s Quarterly Reports on Form 10-Q for the quarters ended March 31, 2024, June 30, 2024 and September 30, 2024, which are each incorporated by reference into this document.

For more information about EnLink, please visit EnLink’s website at www.enlink.com. The information contained on EnLink’s website or accessible through it does not constitute a part of this document.

Elk Merger Sub I, L.L.C.

100 West Fifth Street
Tulsa, Oklahoma 74103
(918) 588-7000

Merger Sub I is a Delaware limited liability company and direct, wholly-owned subsidiary of ONEOK. Merger Sub I has not carried on any activities to date, other than activities incidental to its formation or undertaken in connection with the transactions contemplated by the Merger Agreement.

Elk Merger Sub II, L.L.C.

100 West Fifth Street
Tulsa, Oklahoma 74103
(918) 588-7000

Merger Sub II is a Delaware limited liability company and direct, wholly-owned subsidiary of ONEOK. Merger Sub II has not carried on any activities to date, other than activities incidental to its formation or undertaken in connection with the transactions contemplated by the Merger Agreement.

EnLink Midstream Manager, LLC

100 West Fifth Street
Tulsa, Oklahoma 74103
(918) 588-7000

Manager is a Delaware limited liability company and sole managing member of EnLink. Manager is responsible for conducting the business and managing the operations of EnLink. As of the consummation of the GIP Interest Acquisition on October 15, 2024, ONEOK owns all limited liability company interests in Manager.

SPECIAL MEETING OF ENLINK UNITHOLDERS

General

This proxy statement/prospectus is first being mailed on or about December 31, 2024 and constitutes notice of the EnLink Special Meeting in conformity with the requirements of the EnLink Operating Agreement.

This proxy statement/prospectus is being provided to EnLink unitholders as part of a solicitation of proxies by the EnLink Board for use at the EnLink Special Meeting, including any adjournment or postponement of the EnLink Special Meeting. EnLink unitholders are encouraged to read the entire document carefully, including the annexes to this document, for more detailed information regarding the Merger Agreement and the transactions contemplated by the Merger Agreement.

Date, Time and Place

The EnLink Special Meeting will be held virtually at www.virtualshareholdermeeting.com/ENLC2025SM, on January 30, 2025, at 10:00 a.m., Central Time. The EnLink Special Meeting can be accessed by visiting www.virtualshareholdermeeting.com/ENLC2025SM, where EnLink unitholders will be able to participate and vote online. This proxy statement/prospectus is first being furnished to EnLink’s unitholders on or about December 31, 2024.

Purpose of the EnLink Special Meeting

At the EnLink Special Meeting, EnLink unitholders will be asked to consider and vote on the following:

1.      the Merger Proposal; and

2.      the Non-Binding Advisory Compensation Proposal.

EnLink does not intend to transact any other business at the EnLink Special Meeting or any adjournment or postponement thereof, except such business as may properly be brought before the EnLink Special Meeting by or at the direction of the EnLink Board in accordance with the EnLink Operating Agreement. This proxy statement/prospectus, including the Merger Agreement attached thereto as Annex A, contains further information with respect to these matters.

Recommendation of the EnLink Conflicts Committee and the EnLink Board

The EnLink Conflicts Committee unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, were in the best interests of EnLink and the EnLink Unaffiliated Unitholders, (ii) approved the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, with such approval constituting “Special Approval” for all purposes under the EnLink Operating Agreement, including, but not limited to, Section 7.9(d) thereof, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) recommended that the EnLink Board approve the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and (iv) recommended (A) that the EnLink Board resolve to direct that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders and (B) that the EnLink unitholders approve the Merger Agreement and the Mergers.

The EnLink Board (acting based in part upon the recommendation of the EnLink Conflicts Committee) unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, are in the best interests of EnLink and the EnLink unitholders, (ii) approved the Merger Agreement and the Support Agreement, the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) directed that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders, and (iv) recommended that the EnLink unitholders approve the Merger Agreement.

For a description of factors considered by the EnLink Conflicts Committee in reaching its decision to approve and declare advisable the foregoing proposals, please see the section entitled “The Mergers — Recommendation of the EnLink Conflicts Committee and the EnLink Board and their Reasons for the Mergers” beginning on page 40.

The EnLink Conflicts Committee and the EnLink Board each unanimously recommends that EnLink unitholders vote “FOR” the Merger Proposal. The EnLink Board unanimously recommends that EnLink unitholders vote “FOR” the Non-Binding Advisory Compensation Proposal.

EnLink unitholders’ approval of the Merger Proposal is a condition for the Mergers to occur. If EnLink unitholders fail to approve the Merger Proposal by the requisite vote, the Mergers will not occur. The Non-Binding Advisory Compensation Proposal is not a condition to the consummation of the Mergers.

Record Date; Unitholders Entitled to Vote

Only EnLink unitholders at the close of business on December 23, 2024, the Record Date for the EnLink Special Meeting, will be entitled to notice of, and to vote at, the EnLink Special Meeting or any adjournment or postponement of the EnLink Special Meeting. At the close of business on the Record Date, 457,079,545 EnLink Units were issued and outstanding.

EnLink unitholders are entitled to one vote for each EnLink Unit they own at the close of business on the Record Date.

Quorum; Adjournment

The presence at the EnLink Special Meeting of the holders of a majority of the outstanding EnLink Units entitled to vote at the meeting as of the close of business on the Record Date, represented in person or by proxy, will constitute a quorum. As a result, there must be 228,539,774 EnLink Units represented by proxy or by unitholders present and entitled to vote at the EnLink Special Meeting in order to have a quorum and, for business to be conducted at the EnLink Special Meeting, a quorum must be present. Virtual attendance at the EnLink Special Meeting will constitute presence in person for the purpose of determining the presence of a quorum for the transaction of business at the EnLink Special Meeting.

The Manager may adjourn the meeting from time to time, whether or not there is a quorum. Failure of a quorum to be represented at the EnLink Special Meeting will result in an adjournment of the EnLink Special Meeting and may subject EnLink to additional expense. Even if a quorum is present, the EnLink Special Meeting may also be adjourned in order to provide more time to solicit additional proxies in favor of approval of the Merger Proposal if the Manager determines such adjournment is necessary.

Notice need not be given of the adjourned meeting and a new record date need not be fixed if the time and place thereof are announced at the meeting at which the adjournment is taken unless the adjournment is for more than 45 days, in which case a notice of the adjourned meeting will be given to each unitholder of record entitled to vote at the meeting. If after the adjournment a new record date for the unitholders entitled to vote is fixed for the adjourned meeting, the EnLink Board must fix a record date for the adjourned meeting in accordance with the DLLCA and provide a new notice of the adjourned meeting to each unitholder of record entitled to vote at the meeting. In addition, prior to the date of the EnLink Special Meeting, the Manager may postpone the EnLink Special Meeting one or more times for any reason by giving at least two days’ prior notice to the EnLink unitholders entitled to vote at such meeting in accordance with the EnLink Operating Agreement.

If the EnLink Special Meeting is adjourned or postponed for the purpose of soliciting additional votes, unitholders who have already submitted their proxies will be able to revoke them at any time prior to the final vote on the proposals. If you submit your proxy over the Internet or by telephone or submit a properly executed proxy card, even if you abstain from voting, your units will be counted as present for purposes of determining whether a quorum exists at the EnLink Special Meeting.

Required Vote

Approval of the Merger Proposal requires the affirmative vote of holders of a majority of the outstanding EnLink Units entitled to vote on the proposal. Accordingly, with respect to an EnLink unitholder who is present in person or represented by proxy at the EnLink Special Meeting, such unitholder’s abstention from voting will have

the same effect as a vote “against” the Merger Proposal. Additionally, the failure of an EnLink unitholder who holds EnLink Units in “street name” through a bank, broker or other nominee to give voting instructions to the bank, broker or other nominee will have the same effect as a vote “against” the Merger Proposal.

Approval of the Non-Binding Advisory Compensation Proposal requires the affirmative vote of holders of a majority of the outstanding EnLink Units entitled to vote on the proposal. Accordingly, with respect to an EnLink unitholder who is present in person or represented by proxy at the EnLink Special Meeting, such unitholder’s abstention from voting will have the same effect as a vote “against” the Non-Binding Advisory Compensation Proposal. Additionally, the failure of an EnLink unitholder who holds EnLink Units in “street name” through a bank, broker or other nominee to give voting instructions to the bank, broker or other nominee will have the same effect as a vote “against” the Non-Binding Advisory Compensation Proposal. As an advisory vote, this proposal is not binding upon EnLink, the EnLink Board, ONEOK or the ONEOK Board, and approval of this proposal is not a condition to completion of the Mergers.

The Mergers are conditioned on, among other things, the approval of the Merger Proposal at the EnLink Special Meeting. The Non-Binding Advisory Compensation Proposal is not conditioned on the approval of any other proposal set forth in this proxy statement/prospectus.

Abstentions and Broker Non-Votes

An abstention occurs when a unitholder attends a meeting, either in person or by proxy, but abstains from voting. At the EnLink Special Meeting, abstentions will be counted as present for purposes of determining whether a quorum exists. Abstaining from voting will have the same effect as voting “against” the Merger Proposal and “against” the Non-Binding Advisory Compensation Proposal.

If no instruction as to how to vote is given (including no instruction to abstain from voting) in an executed, duly returned and not revoked proxy, the proxy will be voted “FOR” the Merger Proposal and “FOR” the Non-Binding Advisory Compensation Proposal.

Broker non-votes occur when (i) a bank, broker or other nominee has discretionary authority to vote on one or more proposals to be voted on at a meeting of unitholders but is not permitted to vote on other proposals without instructions from the beneficial owner of the units and (ii) the beneficial owner fails to provide the bank, broker or other nominee with such instructions. Under NYSE rules, banks, brokers and other nominees holding units in “street name” do not have discretionary voting authority with respect to any of the EnLink proposals described in this proxy statement/prospectus. Accordingly, if a beneficial owner of EnLink Units held in “street name” does not give voting instructions to the bank, broker or other nominee, then those units will not be counted as present in person or by proxy at the EnLink Special Meeting and will have the same effect as voting “against” the Merger Proposal and “against” the Non-Binding Advisory Compensation Proposal.

Virtual attendance at the EnLink Special Meeting constitutes presence in person for purposes of the vote required.

Failure to Vote

If you are a unitholder of record and you do not sign and return your proxy card or submit your proxy over the Internet, by telephone or at the EnLink Special Meeting, your units will not be voted at the EnLink Special Meeting, will not be counted as present in person or by proxy at the EnLink Special Meeting and will not be counted as present for purposes of determining whether a quorum exists.

For purposes of the Merger Proposal and the Non-Binding Advisory Compensation Proposal, provided a quorum is present, a failure to vote, or a failure to instruct your bank, broker, trust or other nominee to vote, will have the same effect as a vote “against” the Merger Proposal and “against” the Non-Binding Advisory Compensation Proposal.

An abstention from voting will have the same effect as a vote “against” the Merger Proposal and “against” the Non-Binding Advisory Compensation Proposal.

If you sign, date and return your proxy card and do not indicate how you want your EnLink Units to be voted, then your EnLink Units will be voted “FOR” the Merger Proposal and “FOR” the Non-Binding Advisory Compensation Proposal.

Virtual attendance at the EnLink Special Meeting constitutes presence in person for purposes of the vote required.

Voting by EnLink’s Directors and Executive Officers

At the close of business on December 23, 2024, the Record Date, directors and executive officers of EnLink were entitled to vote 1,949,693 EnLink Units, or approximately 0.4% of the EnLink Units issued and outstanding on that date. EnLink currently expects that all of its directors and executive officers will vote their units in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal, although none of the directors and executive officers are obligated to do so.

Voting by ONEOK

At the close of business on December 23, 2024, the Record Date, ONEOK was entitled to vote 200,340,753 EnLink Units, or approximately 43.8% of the EnLink Units issued and outstanding on that date. Pursuant to the terms of the Support Agreement, ONEOK has irrevocably agreed to vote such units in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal.

Voting at the EnLink Special Meeting

The EnLink Special Meeting will be a completely virtual meeting. There will be no physical meeting location and the meeting will only be conducted via live webcast. The virtual EnLink Special Meeting will be held on January 30, 2025, at 10:00 a.m., Central Time. To participate in the EnLink Special Meeting and submit questions during the special meeting, visit www.virtualshareholdermeeting.com/ENLC2025SM and enter the control number on the proxy card, voting instruction form or notice you received. Online check-in will begin at 9:45 a.m., Central Time. Please allow time for online check-in procedures.

The virtual unitholder meeting format uses technology designed to increase unitholder access, save EnLink and EnLink unitholders time and money, and provide EnLink unitholders rights and opportunities to participate in the meeting similar to what they would have at an in-person meeting. In addition to online attendance, EnLink provides unitholders with an opportunity to hear all portions of the official meeting, submit written questions and comments during the meeting, and vote online during the open poll portion of the meeting. Although EnLink offers four different methods to submit a proxy, EnLink encourages you to submit a proxy either over the Internet or by telephone to ensure that your units are represented and voted at the EnLink Special Meeting.

•        To Submit a Proxy over the Internet:    To submit a proxy over the Internet, follow the instructions provided on your proxy card. You will need the number included on your proxy card to obtain your records and to create an electronic voting instruction form. If you submit your proxy over the Internet, you do not have to mail in a proxy card. If you choose to submit your proxy over the Internet, you must do so prior to 11:59 p.m., Eastern Time, on January 29, 2025.

•        To Submit a Proxy by Telephone:    Registered unitholders may submit a proxy by telephone by calling the toll-free number provided on your proxy card on a touch-tone telephone. Please have your proxy card available for reference because you will need the validation details that are located on your proxy card in order to submit your proxy by telephone. If you submit your proxy by telephone, you do not have to mail in a proxy card. If you choose to submit your proxy by telephone, you must do so prior to 11:59 p.m., Eastern Time, on January 29, 2025.

•        To Submit a Proxy by Mail:    To submit a proxy by mail, complete, sign and date the proxy card and return it promptly to the address indicated on the proxy card in the postage paid enveloped provided. If you sign and return your proxy card without indicating how you want your EnLink Units to be voted with regard to a particular proposal, your EnLink Units will be voted in favor of such proposal. If you return your proxy card without a signature, your units will not be counted as present at the EnLink Special Meeting and cannot be voted.

•        To Vote Virtually at the EnLink Special Meeting:    To vote virtually at the EnLink Special Meeting, follow the instructions at www.virtualshareholdermeeting.com/ENLC2025SM.

If your units are held by your bank, broker or other nominee, you are considered the beneficial owner of units held in “street name” and you will receive a vote instruction form from your bank, broker or other nominee seeking instruction from you as to how your units should be voted.

If you sign your proxy, but do not indicate how you wish to vote, your units will be voted “FOR” the Merger Proposal and “FOR” the Non-Binding Advisory Compensation Proposal.

Revocation of Proxies

You can change or revoke your proxy at any time before the final vote at the EnLink Special Meeting. If you are the unitholder of record of your EnLink Units, you may revoke your proxy by:

•        submitting another proxy over the Internet or by telephone prior to 11:59 p.m., Eastern Time, on January 29, 2025;

•        timely delivering a written notice that you are revoking your proxy to EnLink’s Secretary;

•        timely delivering a valid, later-dated proxy; or

•        attending the EnLink Special Meeting and voting. Your virtual attendance at the EnLink Special Meeting will not revoke your proxy unless you give written notice of revocation to EnLink’s Secretary before your proxy is exercised or unless you vote your units in person at the EnLink Special Meeting.

If you are the beneficial owner of units held in “street name,” you should contact your bank, broker or other nominee with questions about how to change or revoke your voting instructions.

Solicitation of Proxies

The EnLink Board is soliciting your proxy in connection with the EnLink Special Meeting, and EnLink will bear the cost of soliciting such proxies, including the costs of printing and filing this proxy statement/prospectus. EnLink has retained Innisfree M&A Incorporated as proxy solicitor to assist with the solicitation of proxies in connection with the EnLink Special Meeting. In addition to the reimbursement of expenses, EnLink agreed to pay Innisfree M&A Incorporated a fee of up to $75,000 for these services. Solicitation initially will be made by mail. Forms of proxies and proxy materials may also be distributed through banks, brokers and other nominees to the beneficial owners of EnLink Units, in which case these parties will be reimbursed for their reasonable out-of-pocket expenses. Proxies may also be solicited in person or by telephone, facsimile, electronic mail, or other electronic medium by certain of EnLink’s directors, officers and employees, as applicable, without additional compensation.

Tabulation of Votes

Broadridge Financial Solutions, Inc. will tabulate the votes at the EnLink Special Meeting.

No Appraisal Rights

Under the DLLCA, EnLink unitholders are not entitled to appraisal or dissenters’ rights in connection with the Mergers. For additional information, please see the section entitled “The Mergers — No Appraisal Rights.”

Householding of EnLink Special Meeting Materials

Each registered EnLink unitholder will receive one copy of this proxy statement/prospectus per account, regardless of whether you have the same address as another unitholder of record. SEC rules permit companies and intermediaries such as brokers to satisfy delivery requirements for proxy statements and notices with respect to two or more unitholders sharing the same address by delivering a single proxy statement or a single notice addressed to those unitholders. This process, commonly called “householding,” provides cost savings for companies. Some brokers household proxy materials, delivering a single proxy statement or notice to multiple unitholders sharing an address unless contrary instructions have been received from the affected unitholders. For more details, please see the section entitled “Householding of Proxy Materials.”

Questions

If you have more questions about the Mergers or how to submit your proxy, or if you need additional copies of this proxy statement/prospectus or the enclosed proxy card or voting instructions, please contact EnLink’s Secretary, at EnLink’s principal executive offices at 1722 Routh Street, Suite 1300, Dallas, Texas 75201.

Assistance

If you need assistance voting or in completing your proxy card or have questions regarding the EnLink Special Meeting, please contact EnLink’s Solicitation Agent:

Innisfree M&A Incorporated
Unitholders may call toll free: (866) 239-1762
Banks and Brokers may call collect: (212) 750-5833

ENLINK PROPOSAL 1 — THE MERGER PROPOSAL

This proxy statement/prospectus is being furnished to EnLink unitholders as part of the solicitation of proxies by the EnLink Board for use at the EnLink Special Meeting to consider and vote upon a proposal to approve the Merger Agreement, which is attached as Annex A to this proxy statement/prospectus, and the transactions contemplated thereby, including the Mergers.

The EnLink Conflicts Committee unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, were in the best interests of EnLink and the EnLink Unaffiliated Unitholders, (ii) approved the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, with such approval constituting “Special Approval” for all purposes under the EnLink Operating Agreement, including, but not limited to, Section 7.9(d) thereof, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) recommended that the EnLink Board approve the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and (iv) recommended (A) that the EnLink Board resolve to direct that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders and (B) that the EnLink unitholders approve the Merger Agreement and the Mergers.

The EnLink Board (acting based in part upon the recommendation of the EnLink Conflicts Committee) unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, are in the best interests of EnLink and the EnLink unitholders, (ii) approved the Merger Agreement and the Support Agreement, the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) directed that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders, and (iv) recommended that the EnLink unitholders approve the Merger Agreement.

Required Vote of EnLink Unitholders

The EnLink Conflicts Committee and the EnLink Board accordingly each unanimously recommends that EnLink unitholders vote “FOR” the Merger Proposal to approve the Merger Agreement and the Mergers contemplated thereby, as disclosed in this proxy statement/prospectus, particularly the related narrative disclosures in the sections of this proxy statement/prospectus entitled “The Merger” and “The Merger Agreement” and as attached as Annex A to this proxy statement/prospectus.

Approval of the Merger Proposal is a condition to completion of the Mergers.

The vote on the Merger Proposal is a vote separate and apart from the vote to approve the Non-Binding Advisory Compensation Proposal. Accordingly, an EnLink unitholder may vote to approve the Merger Proposal and vote not to approve the Non-Binding Advisory Compensation Proposal, and vice versa.

Approval of the Merger Proposal requires the affirmative vote of holders of a majority of the outstanding EnLink Units entitled to vote thereon. A failure to vote, a broker non-vote or an abstention will have the same effect as a vote “against” the Merger Proposal. Virtual attendance at the EnLink Special Meeting constitutes presence in person for purposes of the vote required.

THE ENLINK CONFLICTS COMMITTEE AND THE ENLINK BOARD EACH UNANIMOUSLY RECOMMENDS THAT YOU VOTE “FOR” THE MERGER PROPOSAL.

ENLINK PROPOSAL 2 — THE NON-BINDING ADVISORY COMPENSATION PROPOSAL

EnLink is asking its unitholders to approve the Non-Binding Advisory Compensation Proposal.

As required by Section 14A of the Exchange Act and the applicable SEC rules issued thereunder, which were enacted pursuant to the Dodd-Frank Wall Street Reform and Consumer Protection Act, EnLink is required to provide its unitholders the opportunity to vote to approve, on a non-binding, advisory basis, certain compensation that may be paid or become payable to EnLink’s named executive officers that is based on or otherwise relates to the Mergers, as described in the section entitled “The Mergers — Interests of Certain EnLink Directors and Executive Officers in the Mergers — Quantification of Potential Payments to EnLink’s Named Executive Officers in Connection with the Mergers” beginning on page 59. Accordingly, EnLink unitholders are being provided the opportunity to cast an advisory vote on such payments.

As an advisory vote, this proposal is not binding upon EnLink, the EnLink Board, ONEOK or the ONEOK Board, and approval of this proposal is not a condition to completion of the Mergers and is a vote separate and apart from the vote to approve the Merger Proposal. Accordingly, an EnLink unitholder may vote to approve the Non-Binding Advisory Compensation Proposal and vote not to approve the Merger Proposal, and vice versa. Because the executive compensation to be paid in connection with the Mergers is based on the terms of the Merger Agreement as well as the contractual arrangements with EnLink’s named executive officers, such compensation will be payable, regardless of the outcome of this advisory vote, only if the Merger Proposal is approved (subject only to the contractual conditions applicable thereto). However, EnLink seeks the support of its unitholders and believes that unitholder support is appropriate because EnLink has a comprehensive executive compensation program designed to link the compensation of the executives of EnLink with EnLink’s performance and the interests of EnLink unitholders.

Accordingly, EnLink unitholders are being asked to vote on the following resolution:

RESOLVED, that the unitholders of EnLink Midstream, LLC approve, on an advisory, non-binding basis, certain compensation that may be paid or become payable to the named executive officers of EnLink Midstream Manager, LLC that is based on or otherwise relates to the Mergers, as disclosed pursuant to Item 402(t) of Regulation S-K under the heading “The Mergers — Interests of Certain EnLink Directors and Executive Officers in the Mergers — Quantification of Potential Payments to EnLink’s Named Executive Officers in Connection with the Mergers,” in the proxy statement/prospectus of EnLink Midstream, LLC with respect to the special meeting of unitholders to be held on January 30, 2025.

Required Vote of Unitholders

The EnLink Board unanimously recommends that EnLink unitholders vote “FOR” the Non-Binding Advisory Compensation Proposal.

Approval of the Non-Binding Advisory Compensation Proposal requires the affirmative vote of holders of a majority of the outstanding EnLink Units entitled to vote thereon. A failure to vote, a broker non-vote or an abstention will have the same effect as a vote “against” the Non-Binding Advisory Compensation Proposal. Virtual attendance at the EnLink Special Meeting constitutes presence in person for purposes of the vote required.

THE ENLINK BOARD UNANIMOUSLY RECOMMENDS THAT YOU VOTE “FOR” THE NON-BINDING ADVISORY COMPENSATION PROPOSAL.

THE MERGERS

The following discussion contains certain information about the proposed Mergers. This discussion is subject, and qualified in its entirety by reference, to the Merger Agreement attached as Annex A to this proxy statement/prospectus. You are urged to carefully read this entire proxy statement/prospectus, including the Merger Agreement, before making any investment or voting decision.

Structure of the Mergers

Pursuant to the Merger Agreement, (i) at the First Merger Effective Time, Merger Sub I will merge with and into EnLink, the separate existence of Merger Sub I will cease and EnLink will survive and continue to exist and (ii) promptly following the First Merger, but in any event on the same day as the First Merger and as part of the same overall transaction as the First Merger, at the Effective Time, EnLink, as the surviving entity in the First Merger, will merge with and into Merger Sub II, the separate existence of EnLink will cease and Merger Sub II shall survive and continue to exist as a direct, wholly-owned subsidiary of ONEOK. Following the Mergers, EnLink Units will be delisted from the NYSE, will be deregistered under the Exchange Act as promptly as practicable after the First Merger Effective Time and will cease to be publicly traded.

Support Agreement

In connection with the entry into the Merger Agreement, ONEOK and EnLink entered into the Support Agreement. Pursuant to the Support Agreement, ONEOK, which beneficially owns 200,340,753 EnLink Units, representing approximately 43.8% of the EnLink Units outstanding as of the Record Date, has irrevocably agreed to vote such units (i) in favor of the Merger Proposal and the Non-Binding Advisory Compensation Proposal; and (ii) against any action, agreement or transaction that would reasonably be expected to impede, interfere with, delay, postpone, discourage, frustrate the purposes of or adversely affect the merger or the other transactions contemplated by the Merger Agreement. The Support Agreement will terminate automatically upon the earliest to occur of (i) the First Merger Effective Time; (ii) the termination of the Merger Agreement in accordance with its terms, other than as a result of a breach by ONEOK of the terms of the Support Agreement; or (iii) the mutual agreement of the parties thereto.

The foregoing description of the Support Agreement is qualified in its entirety by reference to the full text of the Support Agreement, a copy of which is attached as Annex C to this proxy statement/prospectus and is incorporated into this proxy statement/prospectus by reference.

Background of the Mergers

On August 28, 2024, ONEOK announced that it executed a definitive agreement with GIP III Stetson I, L.P. and GIP III Stetson II, L.P. to acquire Global Infrastructure Partners’ (“GIP”) entire interest in EnLink, consisting of 43% of the EnLink Units for $14.90 per unit, and 100% of the interests in the Manager for $300 million, for total cash consideration of approximately $3.3 billion. As part of that announcement, ONEOK also publicly stated that, after the closing of the GIP Interest Acquisition, ONEOK intended to pursue the acquisition of the publicly owned equity interest in EnLink (the “EnLink Unaffiliated Units”) in a tax-free transaction.

In light of ONEOK’s publicly stated intention to pursue the acquisition of the EnLink Unaffiliated Units following closing of the GIP Interest Acquisition, on September 6, 2024, the EnLink Conflicts Committee, a representative of Baker Botts L.L.P. (“Baker Botts”) and EnLink management participated on a call to discuss the role of the EnLink Conflicts Committee in connection with a future potential transaction with ONEOK, the process for evaluating such a potential transaction, the role of the legal counsel and financial advisor to the EnLink Conflicts Committee and recommendations with respect thereto, the independence of the members of the EnLink Conflicts Committee and an indicative timeline with respect to the potential transaction.

Between September 6, 2024 and October 14, 2024, the EnLink Conflicts Committee had a series of preliminary meetings to interview potential financial advisors and legal counsel. The EnLink Conflicts Committee interviewed potential legal advisors, including Richards, Layton & Finger, P.A. (“RLF”), and determined, based on RLF’s experience with public mergers and acquisitions, complex transactions involving publicly traded limited partnerships and limited liability companies, RLF’s familiarity with EnLink and its business and representations of conflicts committees generally, that RLF had the requisite expertise and was

well qualified to advise the EnLink Conflicts Committee. On September 10, 2024, RLF was selected by the EnLink Conflicts Committee as legal counsel in connection with the potential transaction. The EnLink Conflicts Committee also interviewed potential financial advisors, including Evercore. Based on Evercore’s experience with public mergers and acquisitions, complex transactions involving publicly traded partnerships and limited liability companies, Evercore’s familiarity with EnLink and its business and representations of conflicts committees generally, the EnLink Conflicts Committee determined that Evercore had the requisite expertise and was well qualified to advise the EnLink Conflicts Committee.

On October 14, 2024, the EnLink Board delegated to the EnLink Conflicts Committee the power and authority (i) to make such investigation of the proposed transaction and the alternative of maintaining the status quo, as the EnLink Conflicts Committee deems necessary or appropriate; (ii) to review, evaluate and negotiate (or to supervise and direct the negotiations on behalf of EnLink with respect to) the terms and conditions, and determine the advisability, of the proposed transaction and related agreements and arrangements; (iii) to determine whether the proposed transaction is in, or not opposed to, the best interests of EnLink; (iv) to determine whether to approve the proposed transaction (with such approval constituting “Special Approval” for all purposes under the EnLink Operating Agreement, including, but not limited to, Section 7.9(d) thereof), and to make a recommendation to the EnLink Board whether to approve the proposed transaction and, if appropriate, to recommend that the EnLink unitholders approve the proposed transaction; and (v) to make any other recommendations to the EnLink Board and/or the EnLink unitholders regarding the proposed transaction as the EnLink Conflicts Committee determines to be appropriate.

On October 15, 2024, ONEOK and GIP closed the GIP Interest Acquisition, and Pierce H. Norton II, President and Chief Executive Officer of ONEOK, Walter S. Hulse III, Chief Financial Officer, Treasurer, and Executive Vice President, Investor Relations and Corporate Development of ONEOK, and Lyndon C. Taylor, Executive Vice President, Chief Legal Officer and Assistant Secretary of ONEOK, were appointed to serve as members of the EnLink Board, with Mr. Norton serving as the Chairman of the EnLink Board.

On October 17, 2024, the EnLink Conflicts Committee met with representatives of ONEOK and RLF. The ONEOK representatives informed the EnLink Conflicts Committee that ONEOK successfully closed the GIP Interest Acquisition and that an offer to acquire the EnLink Unaffiliated Units would be forthcoming the next day.

On October 18, 2024, ONEOK delivered an unsolicited, non-binding proposal (the “Initial ONEOK Offer”) to Tiffany Cepak, the Chair of the EnLink Conflicts Committee, setting forth certain terms of the proposed tax-free transaction, pursuant to which ONEOK would acquire all of the outstanding EnLink Unaffiliated Units in exchange for shares of ONEOK Common Stock equal to consideration of $14.70 per EnLink Unit. Accompanying the Initial ONEOK Offer was an initial draft of the Merger Agreement prepared by representatives of Kirkland & Ellis LLP (“K&E”), legal counsel to ONEOK. The initial draft of the Merger Agreement provided, among other terms, (i) that the EnLink Board or the EnLink Conflicts Committee could only effect an adverse recommendation change if an intervening event occurred and if the EnLink Board or the EnLink Conflicts Committee, as applicable, after consultation with its financial advisors and outside legal counsel, determined in good faith that failure to take such action would be inconsistent with its duties under the EnLink Operating Agreement and applicable law; (ii) for a “force the vote” provision that required EnLink to hold the EnLink Special Meeting even if the EnLink Board or the EnLink Conflicts Committee made an adverse recommendation change; (iii) for the approval of the Mergers by the holders of a majority of the EnLink Units held by all EnLink unitholders; and (iv) that EnLink would be liable for a termination fee payable to ONEOK if ONEOK terminated the Merger Agreement prior to the EnLink unitholder approval due to an adverse recommendation change. The Merger Agreement did not contemplate delivery of a support agreement whereby ONEOK would agree to vote the EnLink Units it holds in favor of the Mergers.

On October 21, 2024, Evercore’s engagement as financial advisor to the EnLink Conflicts Committee was finalized pursuant to an engagement letter agreed to by the EnLink Conflicts Committee, EnLink and Evercore, and Evercore provided a letter documenting Evercore’s lack of recent relationships with EnLink, the Manager and ONEOK.

On October 22, 2024, the EnLink Conflicts Committee met with representatives of Evercore and RLF. The EnLink Conflicts Committee and its advisors reviewed and discussed a preliminary due diligence request list prepared by Evercore and the process for evaluating the proposed transaction and the Initial ONEOK Offer from a financial point of view. The EnLink Conflicts Committee instructed Evercore to finalize the due diligence request list, requesting certain financial, legal and other due diligence information with respect to EnLink and ONEOK, as

applicable. Following such meeting, Evercore sent an initial due diligence request list to the ONEOK management team, which the ONEOK management team sent to the EnLink management team to provide such requested information applicable to EnLink.

On October 28, 2024, the EnLink Conflicts Committee met with representatives of Evercore, RLF and management of EnLink. During the meeting, management of EnLink presented information on, among other things, the recent performance of EnLink, financial updates regarding EnLink and a business overview of EnLink and its assets. Following such meeting, the EnLink Conflicts Committee, representatives of Evercore and RLF and certain members of management of EnLink met with Mr. Hulse. Mr. Hulse presented the terms of, and the rationale for, the Initial ONEOK Offer. Mr. Hulse noted that, in connection with the GIP Interest Acquisition, ONEOK provided GIP with letters on June 24, 2024 and on July 11, 2024 proposing to acquire all of the equity interests in EnLink (collectively, the “GIP Offer Letters”). Mr. Hulse explained that GIP wanted to negotiate its sale of approximately 43% of the outstanding EnLink Units and all of the equity interests in the Manager separate from any negotiation regarding the acquisition of publicly held EnLink Units and, thus, ONEOK and GIP proceeded on that basis.

On October 29, 2024, the EnLink Conflicts Committee met with representatives of Evercore and RLF. The EnLink Conflicts Committee and its advisors discussed their reactions to the information presented by the representatives of management of EnLink and Mr. Hulse. During the meeting, the EnLink Conflicts Committee noted that they had not been aware of the existence of the GIP Offer Letters and instructed Evercore to request copies of those letters.

On October 30, 2024, Mr. Hulse provided copies of the GIP Offer Letters to the EnLink Conflicts Committee, Evercore and RLF.

On November 5, 2024, representatives of Baker Botts and RLF had a call with EnLink management to discuss the material terms of the initial draft of the Merger Agreement provided by K&E.

On November 7, 2024, the EnLink Conflicts Committee met with representatives of Evercore and RLF. During the meeting, representatives of RLF explained the duties of the EnLink Conflicts Committee in connection with the proposed transaction, provided an update on a proposed plan for negotiating the Merger Agreement, discussed legal implications of the GIP Offer Letters, and discussed legal matters and process issues relating to the potential transaction. Representatives of Evercore presented their preliminary financial analysis with respect to the proposed transaction. During its presentation, Evercore, among other things, reviewed the terms of the Initial ONEOK Offer, the capital structure of EnLink, historical trading prices of the EnLink Units and ONEOK Common Stock and Evercore’s diligence with management of EnLink and ONEOK, including EnLink’s financial forecasts and management’s responses to Evercore’s diligence questions. Evercore then presented its preliminary valuation of the EnLink Units. Following discussion, the EnLink Conflicts Committee directed Evercore to, on behalf of the EnLink Conflicts Committee, contact ONEOK and propose an exchange ratio implying that EnLink Unaffiliated Units be exchanged for shares of ONEOK Common Stock equal to consideration of $18.25 per EnLink Unit and that the proposed transaction be conditioned upon receiving (i) a support agreement from ONEOK, and (ii) the approval of holders of a majority of the EnLink Units held by the EnLink Unaffiliated Unitholders (a “Majority of the Minority” and such counterproposal, the “First EnLink Counterproposal”).

On November 8, 2024, representatives of Evercore communicated the First EnLink Counterproposal to Mr. Hulse. On the same day, Mr. Hulse contacted Evercore and rejected the First EnLink Counterproposal, proposing instead that the EnLink Unaffiliated Units be exchanged for shares of ONEOK Common Stock equal to consideration of $15.25 per EnLink Unit and noted that ONEOK would agree to provide a Support Agreement in connection with the proposed transaction (the “Second ONEOK Offer”). As part of the Second ONEOK Offer, ONEOK also rejected the EnLink Conflicts Committee’s proposal that the proposed transaction be conditioned upon receiving the approval of a Majority of the Minority.

On November 11, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. During the meeting, representatives of Evercore reported on the Second ONEOK Offer and presented Evercore’s revised financial analysis of the proposed transaction and the Second ONEOK Offer. The EnLink Conflicts Committee determined not to make a counteroffer at the meeting, and instructed Evercore to conduct additional diligence regarding EnLink’s business opportunities and growth projects with management of EnLink.

On November 12, 2024, representatives of Evercore met with EnLink management to discuss EnLink’s business opportunities and growth projects.

On November 12, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. Evercore presented additional financial analysis to the EnLink Conflicts Committee regarding the proposed transaction and the Second ONEOK Offer and discussed Evercore’s conversation with management of EnLink regarding EnLink’s business opportunities and growth projects. The EnLink Conflicts Committee and its advisors then discussed the Second ONEOK Offer and potential responses thereto. Following the discussion, the EnLink Conflicts Committee determined to propose that the EnLink Unaffiliated Units be exchanged for shares of ONEOK Common Stock equal to consideration of $17.00 per EnLink Unit and that the proposed transaction be conditioned upon receiving the approval of a Majority of the Minority (the “Second EnLink Counterproposal”). The EnLink Conflicts Committee instructed Evercore to, on behalf of the EnLink Conflicts Committee, communicate the Second EnLink Counterproposal to Mr. Hulse.

Later on November 12, 2024, representatives of Evercore communicated the Second EnLink Counterproposal to Mr. Hulse. Mr. Hulse rejected the Second EnLink Counterproposal, proposing instead that the EnLink Unaffiliated Units be exchanged for shares of ONEOK Common Stock equal to consideration of $15.50 per EnLink Unit (the “Third ONEOK Offer”). As part of the Third ONEOK Offer, ONEOK also rejected the EnLink Conflicts Committee’s proposal that the proposed transaction be conditioned upon receiving the approval of a Majority of the Minority.

On November 15, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. Evercore presented additional financial analysis to the EnLink Conflicts Committee regarding the proposed transaction and the Third ONEOK Offer. Following the discussion, the EnLink Conflicts Committee discussed proposing that the EnLink Unaffiliated Units be exchanged for shares of ONEOK Common Stock equal to consideration of at least a minimum of $16.75 per EnLink Unit and that the proposed transaction be conditioned upon receiving the approval of a Majority of the Minority (the “Third EnLink Counterproposal”). Further, during this meeting, representatives of RLF described to the EnLink Conflicts Committee the material terms of the initial draft of the Merger Agreement provided by K&E, the draft of Support Agreement provided by Baker Botts, and potential revisions to both the draft Merger Agreement and Support Agreement. Following discussion, the EnLink Conflicts Committee determined not to provide comments to the initial draft of the Merger Agreement or circulate the Support Agreement to K&E at that time.

On November 17, 2024, the EnLink Conflicts Committee instructed Evercore to, on behalf of the EnLink Conflicts Committee, communicate the Third EnLink Counterproposal to Mr. Hulse the following day.

On November 18, 2024, representatives of Evercore communicated the Third EnLink Counterproposal to Mr. Hulse. On the same day, Mr. Hulse contacted Evercore and rejected the Third EnLink Counterproposal, proposing instead that the EnLink Unaffiliated Units be exchanged for shares of ONEOK Common Stock equal to consideration of $15.60 per EnLink Unit (the “Fourth ONEOK Offer”). As part of the Fourth ONEOK Offer, ONEOK also rejected the EnLink Conflicts Committee’s proposal that the proposed transaction be conditioned upon receiving the approval of a Majority of the Minority.

On November 20, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. Evercore presented additional financial analysis to the EnLink Conflicts Committee regarding the proposed transaction and the Fourth ONEOK Offer. During its presentation, Evercore reviewed, among other things, ONEOK’s recent stock price appreciation. The EnLink Conflicts Committee determined not to make a counteroffer at the meeting but instructed Evercore to contact Mr. Hulse to reiterate the EnLink’s Conflicts Committee’s views as to the value of the EnLink Units.

On November 21, 2024, prior to representatives of Evercore contacting Mr. Hulse, Mr. Hulse contacted Evercore and suggested, contingent upon ONEOK Board approval, that the exchange ratio to be used in the proposed transaction be determined by dividing $15.75 (as the proposed value for the EnLink Units) by ONEOK’s 5-day volume-weighted average price (the “Fifth ONEOK Offer”). As part of the Fifth ONEOK Offer, ONEOK also clarified that the proposed transaction would not be conditioned upon receiving the approval of a Majority of the Minority.

Later on November 21, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. During the meeting, representatives of Evercore reported the terms of the Fifth ONEOK Offer to the EnLink Conflicts Committee, noting that the Fifth ONEOK Offer implied a $16.45 per EnLink Unit price based on ONEOK’s closing price on November 20, 2024. The representatives of Evercore presented their updated financial analysis of the proposed transaction and the Fifth ONEOK Offer. Following discussion of potential counteroffers to the Fifth ONEOK Offer, the EnLink Conflicts Committee directed Evercore to, on behalf of the EnLink Conflicts Committee, contact ONEOK and propose an exchange ratio be determined by dividing $15.75 (as the proposed value for the EnLink Units) by ONEOK’s 10-day volume-weighted average price (the “Final EnLink Counterproposal”). The EnLink Conflicts Committee further directed Evercore to, on behalf of the EnLink Conflicts Committee, inform ONEOK that the Final EnLink Counterproposal would not be conditioned upon the proposed transaction receiving the approval of a Majority of the Minority so long as ONEOK would agree to use ONEOK’s 10-day volume-weighted average price. Representatives of RLF then described to the EnLink Conflicts Committee proposed revisions to the initial draft of the Merger Agreement, including, among other things, the addition of (i) an ability for the EnLink’s Conflicts Committee to change its recommendation to the EnLink Unaffiliated Unitholders if it determines that the Mergers are no longer in the best interest of the EnLink Unaffiliated Unitholders irrespective of whether an intervening event had occurred; (ii) a mutual expense reimbursement provision payable upon termination of the Merger Agreement following a breach by the other party; (iii) a requirement that, if EnLink pays a distribution for any quarter, such distribution will be no less than $0.1325 per EnLink Unit; and (iv) a requirement that the EnLink Conflicts Committee approve any amendments or waivers to the Merger Agreement. Following such discussion, the EnLink’s Conflicts Committee instructed RLF to finalize the comments to the draft Merger Agreement and draft Support Agreement, and to send the documents to K&E.

Later on November 21, 2024, representatives of Evercore communicated the Final EnLink Counterproposal to Mr. Hulse, and RLF and Baker Botts provided comments to the draft Merger Agreement and an initial draft Support Agreement to K&E. Mr. Hulse informed Evercore that ONEOK would consider the Final EnLink Counterproposal and ONEOK would provide a response on November 22, 2024.

On November 22, 2024, Mr. Hulse contacted Evercore and accepted the Final EnLink Counterproposal, contingent upon ONEOK Board approval and negotiation of terms of the definitive Merger Agreement. On November 22, 2024, Baker Botts sent an initial draft of the EnLink disclosure schedule to K&E.

On November 22, 2024, K&E sent a revised draft of the Merger Agreement to RLF and Baker Botts. The revised draft Merger Agreement, among other things, (a) removed a provision allowing the EnLink Conflicts Committee to make an adverse recommendation change in the event that the EnLink Conflicts Committee determines that the failure to do so would be in the best interest of the EnLink Unaffiliated Unitholders; (b) reinstated a requirement that an adverse recommendation change required the occurrence of an intervening event; (c) removed certain interim operating covenants applicable to ONEOK; (d) proposed that the termination fee payable by EnLink in the event that the Merger Agreement is terminated following an adverse recommendation change by the EnLink Conflicts Committee be an amount equal to 2.5% of EnLink’s equity value; (e) proposed that the mutual expense reimbursement provisions payable by either EnLink or ONEOK in the event that the Merger Agreement is terminated following a material breach by the other party be up to an amount equal to 1.0% of EnLink’s equity value; and (f) otherwise accepted almost all other revisions that the EnLink Conflicts Committee had proposed to the initial draft of the Merger Agreement that K&E had prepared.

On November 23, 2024, representatives of Baker Botts and RLF had a call with EnLink management to discuss the revised draft of the Merger Agreement. Later on November 23, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. During the meeting, representatives of Evercore reviewed the terms of the proposed transaction with the EnLink Conflicts Committee, noting that the exchange ratio created by ONEOK’s 10-day volume-weighted average price based on ONEOK’s closing price on November 22, 2024 was 0.1412 shares of ONEOK Common Stock for each EnLink Unit, which implied a $16.53 per EnLink Unit price based on ONEOK’s November 22, 2024 closing price. During the meeting, RLF described to the EnLink Conflicts Committee the open issues in the draft of the Merger Agreement and a draft of the joint press release to be issued in connection with the proposed transaction.

On November 23, 2024 and November 24, 2024, representatives of K&E, RLF and Baker Botts exchanged additional comments to the draft Merger Agreement, the EnLink disclosure schedules and the Support Agreement. As a result of these exchanges, the Merger Agreement (i) retained a provision allowing the EnLink Conflicts

Committee to make an adverse recommendation change in the event that the EnLink Conflicts Committee determines in good faith that failure to take such action would be inconsistent with its duties under the EnLink Operating Agreement and applicable law; (ii) provided for a termination fee payable by EnLink in the event that the Merger Agreement is terminated following an adverse recommendation change by the EnLink Conflicts Committee in an amount equal to 2.0% of EnLink’s equity value; and (iii) provided for a mutual expense reimbursement in an amount up to $10 million payable by either EnLink or ONEOK in the event that the Merger Agreement is terminated following a material breach by the other party.

On November 24, 2024, the EnLink Conflicts Committee held a meeting with representatives of Evercore and RLF. During the meeting, the EnLink Conflicts Committee and its advisors discussed the proposed transaction, including the terms and conditions of the Merger Agreement, and RLF presented to the EnLink Conflicts Committee an overview and update with respect to the terms of the Merger Agreement. Also at this meeting, Evercore reviewed its updated financial analysis of the proposed transaction with the EnLink Conflicts Committee and, at the request of the EnLink Conflicts Committee, rendered an oral opinion to the EnLink Conflicts Committee, which was subsequently confirmed by delivery of a written opinion dated November 24, 2024, to the effect that, as of the date of such opinion and subject to the factors, procedures, assumptions, qualifications and limitations set forth therein, the Exchange Ratio is fair, from a financial point of view, to the EnLink Unaffiliated Unitholders. At this meeting, the EnLink Conflicts Committee unanimously (i) determined that the proposed Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, were in the best interests of EnLink and the EnLink Unaffiliated Unitholders; (ii) approved the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, with such approval constituting “Special Approval” for all purposes under the EnLink Operating Agreement, including, but not limited to, Section 7.9(d) thereof, and the execution, delivery and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) recommended that the EnLink Board approve the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and (iv) recommended that (A) the EnLink Board resolve to direct that the Merger Agreement and the approval of the Mergers be submitted to a vote of the holders of the EnLink Units and (B) the holders of the EnLink Units approve the Merger Agreement and the Mergers.

Further, on November 24, 2024, following the receipt of the recommendation of the EnLink Conflicts Committee, the EnLink Board, by unanimous approval, (i) determined that the proposed transaction, on the terms and conditions sets forth in the Merger Agreement and the Support Agreement, is in the best interests of EnLink and the EnLink unitholders, (ii) approved the Merger Agreement and the Support Agreement, the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) directed that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders and (iv) resolved to recommend that the EnLink unitholders approve the Merger Agreement.

Subsequently on November 24, 2024, (i) EnLink, the Manager, ONEOK, Merger Sub I and Merger Sub II executed and delivered the Merger Agreement and (ii) ONEOK and EnLink executed and delivered the Support Agreement.

On November 24, 2024, ONEOK and EnLink issued a joint press release announcing the execution of the Merger Agreement.

On November 25, 2024, each of ONEOK and EnLink filed a Current Report on Form 8-K with respect to the Merger Agreement and Support Agreement, and attaching the joint press release and an employee communication.

Recommendation of the EnLink Conflicts Committee and the EnLink Board and their Reasons for the Mergers

The EnLink Board directed the EnLink Conflicts Committee, comprised solely of three independent directors, Ms. Cepak, Ms. Adams and Mr. Echols, who meet the requirements for membership on the EnLink Conflicts Committee set forth in the EnLink Operating Agreement, (i) to make an investigation of the potential transaction and the alternative of maintaining the status quo, as the EnLink Conflicts Committee deems necessary or appropriate, (ii) to review, evaluate, and negotiate (or to supervise and direct the negotiations on behalf of EnLink with respect to) the terms and conditions, and determine the advisability, of the potential transaction and related agreements and arrangements, (iii) to determine whether the potential transaction is in, or not opposed to,

the best interests of EnLink, (iv) to determine whether to approve the potential transaction (with such approval constituting “Special Approval” for all purposes under the EnLink Operating Agreement, including, but not limited to, Section 7.9(d) thereof), and to make a recommendation to the EnLink Board whether to approve the potential transaction and, if appropriate, to recommend that the EnLink unitholders approve the potential transaction, it being understood that any potential transaction is subject to (A) the receipt of a proposal from ONEOK and (B) the approval of the EnLink Board and, in accordance with Section 5.6(b) of the Second Amended and Restated Limited Liability Company Agreement of EnLink Midstream Manager, LLC, dated as of July 18, 2018 (as amended or supplemented, the “Manager LLCA”), ONEOK, in its capacity as sole member of the Manager of the potential transaction, and (v) to make any other recommendations to the EnLink Board and/or the EnLink unitholders regarding the potential transaction as the EnLink Conflicts Committee shall determine to be appropriate. The EnLink Conflicts Committee retained Richards, Layton & Finger, P.A. (“RLF”) as its legal counsel, and Evercore as its financial advisor. The EnLink Conflicts Committee oversaw the performance of financial, legal and other due diligence by its advisors, conducted an extensive review and evaluation of the potential transaction and conducted negotiations with ONEOK and its representatives with respect to the Merger Agreement and the Support Agreement and the transactions contemplated thereby.

On November 24, 2024, the EnLink Conflicts Committee considered the benefits of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, as well as the associated risks, and unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, were in the best interests of EnLink and the EnLink Unaffiliated Unitholders, (ii) approved the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, with such approval constituting “Special Approval” for all purposes under the EnLink Operating Agreement, including, but not limited to, Section 7.9(d) thereof, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) recommended that the EnLink Board approve the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, including the Mergers, and (iv) recommended (A) that the EnLink Board resolve to direct that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders and (B) that the EnLink unitholders approve the Merger Agreement and the Mergers.

The EnLink Board (acting based in part upon the recommendation of the EnLink Conflicts Committee) unanimously (i) determined that the Mergers, on the terms and conditions set forth in the Merger Agreement and the Support Agreement, are in the best interests of EnLink and the EnLink unitholders, (ii) approved the Merger Agreement and the Support Agreement, the execution, delivery, and performance of the Merger Agreement and the Support Agreement and the transactions contemplated thereby, (iii) directed that the Merger Agreement and the approval of the Mergers be submitted to a vote of the EnLink unitholders, and (iv) recommended that the EnLink unitholders approve the Merger Agreement.

The EnLink Conflicts Committee considered the following factors, the order of which does not necessarily reflect their relative significance, to be generally positive or favorable to EnLink and the EnLink Unaffiliated Unitholders in making its determination and approvals and the related recommendation to the EnLink Board:

•        The exchange ratio of 0.1412 shares of ONEOK Common Stock for each EnLink Unit represents an implied value for the EnLink Units of $16.53 per EnLink Unit, which was an implied 25.6% premium to the value of the EnLink Units based upon the closing price of EnLink Units on August 28, 2024 (the unaffected trading price prior to ONEOK’s public announcement of the GIP Interest Acquisition and its intention to pursue a buy-in transaction).

•        The EnLink Conflicts Committee’s belief that the exchange ratio of 0.1412 shares of ONEOK Common Stock for each outstanding EnLink Unit held by the EnLink Unaffiliated Unitholders provides greater value to the EnLink Unaffiliated Unitholders than the long-term value of EnLink as a standalone publicly traded company, after taking into account, among other things, EnLink’s future growth prospects following ONEOK’s purchase of the managing member interest of EnLink.

•        The ONEOK Common Stock that EnLink Unaffiliated Unitholders will receive in the Mergers is more liquid than EnLink Units based on the larger daily trading volume of shares of ONEOK Common Stock, which was trading approximately 10x the dollar volume of EnLink Units on a daily basis as of the time of the EnLink Conflicts Committee’s approval, ONEOK’s broader investor base, and the larger public float of shares of ONEOK Common Stock.

•        The Mergers will result in EnLink Unaffiliated Unitholders becoming equity owners in a combined business with more diversified assets, an investment grade credit rating and more growth opportunities than EnLink on a standalone basis.

•        The holders of shares of ONEOK Common Stock (and the EnLink Unaffiliated Unitholders as a result of receiving shares of ONEOK Common Stock in the First Merger) will benefit from synergies, including reduced SEC filing requirements and a reduction in the number of public company boards.

•        The potential transaction is expected to be immediately accretive to the EnLink Unaffiliated Unitholders with regard to dividends per share of ONEOK Common Stock pro forma for the Mergers versus distributions per EnLink Unit on a standalone basis.

•        The potential transaction is expected generally to be non-taxable to the EnLink Unaffiliated Unitholders.

•        The financial analyses prepared by Evercore during the course of the deliberations and negotiations and the oral opinion of Evercore rendered to the EnLink Conflicts Committee on November 24, 2024 (which was subsequently confirmed in writing by delivery of Evercore’s written opinion addressed to the EnLink Conflicts Committee dated November 24, 2024), to the effect that, as of the date of such opinion, and based upon and subject to the assumptions, limitations, qualifications, and conditions described in Evercore’s written opinion, the exchange ratio of 0.1412 shares of ONEOK Common Stock for each outstanding EnLink Unit to be received in the First Merger is fair, from a financial point of view, to the EnLink Unaffiliated Unitholders.

•        The exchange ratio of 0.1412 shares of ONEOK Common Stock for each outstanding EnLink Unit held by the EnLink Unaffiliated Unitholders is fixed and therefore the implied value of the consideration payable to the EnLink Unaffiliated Unitholders will increase in the event that the market price of ONEOK stock increases prior to the closing of the Mergers.

•        The terms and conditions of the Merger Agreement, which were determined through arm’s-length negotiations between the EnLink Conflicts Committee and ONEOK and their respective representatives and advisors.

•        The negotiated terms of the Merger Agreement, principally:

•        Provisions permitting the EnLink Conflicts Committee to change or withdraw its recommendation to the EnLink unitholders in favor of the Mergers if the EnLink Conflicts Committee determines in good faith that failure to take such action would be inconsistent with its duties under the EnLink Operating Agreement and applicable law.

•        Provisions restricting any elimination of the EnLink Conflicts Committee, revocation or diminution of the authority of the EnLink Conflicts Committee and removal of the members of the EnLink Conflicts Committee between signing of the Merger Agreement and closing of the Mergers.

•        Provisions obligating ONEOK to pay the reasonably documented out-of-pocket expenses incurred by EnLink and its affiliates in connection with the Mergers up to a maximum amount of $10.0 million if the Merger Agreement is terminated under certain circumstances.

•        Provisions restricting amendment of the Merger Agreement without the approval of the EnLink Conflicts Committee.

•        The agreement by ONEOK to vote its EnLink Units in favor of the Merger Agreement and the transactions contemplated thereby.

•        The Mergers are not subject to a vote of ONEOK’s stockholders.

•        ONEOK is governed with a C-corporation structure that will provide governance protections and shareholder rights for the EnLink Unaffiliated Unitholders, which they do not have today.

•        Financial and legal advice provided to the EnLink Conflicts Committee during its deliberations and the negotiation of the Mergers, and the EnLink Conflicts Committee’s engagement of financial and legal advisors with knowledge and experience with respect to public merger and acquisition transactions, EnLink’s industry generally, and EnLink in particular, as well as substantial experience advising companies with respect to transactions similar to the Mergers.

The EnLink Conflicts Committee considered the following factors, the order of which does not necessarily reflect their relative significance, to be potentially negative or unfavorable in arriving at its determination and approvals, and the related recommendation to the EnLink Board:

•        The EnLink Conflicts Committee was not authorized to and did not conduct an auction process or other solicitation of interest from third parties for the acquisition of EnLink Units. Since ONEOK indirectly controls EnLink, it was unrealistic to expect an unsolicited third-party acquisition proposal to acquire assets or control of EnLink, and it was unlikely that the EnLink Conflicts Committee could conduct a meaningful process to solicit interest in the acquisition of assets or control of EnLink.

•        EnLink Unaffiliated Unitholders will be foregoing the potential benefits, if any, that could be realized by EnLink on a standalone basis.

•        The exchange ratio of 0.1412 shares of ONEOK Common Stock for each outstanding EnLink Unit held by the EnLink Unaffiliated Unitholders is fixed and therefore the implied value of the consideration payable to the holders of EnLink Unaffiliated Units will decrease in the event that the market price of ONEOK stock decreases prior to the closing of the Mergers.

•        The vote required to approve the Mergers, which is not subject to approval by majority vote of the EnLink Unaffiliated Unitholders.

•        Even if the EnLink Conflicts Committee were to withdraw or change its recommendation to the EnLink unitholders regarding the Mergers, EnLink would still be required to call a unitholder meeting to vote on the approval of the Mergers and ONEOK owns approximately 44% of the outstanding EnLink Units.

•        Certain terms of the Merger Agreement, principally:

•        Provisions obligating EnLink to pay a termination fee to ONEOK equal to $143,978,000 if the Merger Agreement is terminated under certain circumstances.

•        Provisions obligating EnLink to pay the reasonably documented out-of-pocket expenses incurred by ONEOK and its affiliates in connection with the Mergers up to a maximum amount of $10.0 million if the Merger Agreement is terminated under certain circumstances.

•        Provisions restricting the conduct of EnLink’s business during the interim period between signing of the Merger Agreement and closing of the Mergers.

•        Relatively limited interim operating covenants restricting the operation of ONEOK’s business during the period between signing of the Merger Agreement and closing of the Mergers.

•        Potential risks or delay in consummating the Mergers, meaning there can be no assurance that all conditions to the parties’ obligations to complete the Mergers will be satisfied, and thus it is possible that the Mergers may not be completed in a timely manner or at all.

•        Potential risks if the Mergers are not completed, with potential disruption to the business of EnLink and a potential decline in the trading price of EnLink Units.

•        The risk that litigation may occur in connection with the Mergers, and that any such litigation may result in delay, significant costs and a diversion of management’s focus on the conduct of the business of EnLink.

•        EnLink has incurred and will continue to incur transaction costs and expenses in connection with the Mergers, whether or not the Mergers are completed.

•        EnLink and some of the executive officers and directors of the EnLink Board have interests in the Mergers that are different from, or in addition to, the interests of the EnLink Unaffiliated Unitholders generally.

The foregoing discussion of the information and factors considered by the EnLink Conflicts Committee is not intended to be exhaustive, but includes material factors the EnLink Conflicts Committee and the EnLink Board considered. In view of the variety of factors considered in connection with its evaluation of the Mergers and the complexity of these matters, the EnLink Conflicts Committee and EnLink Board did not find it useful and did not attempt to quantify or assign any relative or specific weights to the various factors considered in making its determination and recommendation. In addition, each of the members of the EnLink Conflicts Committee or the EnLink Board may have given differing weights to different factors. Overall, the EnLink Conflicts Committee and the EnLink Board believed that the positive factors supporting the Merger outweighed the negative factors it considered.

Certain Unaudited Forecasted Financial Information of EnLink

Neither ONEOK nor EnLink, as a matter of course, makes public long-term forecasts or internal projections as to future performance, revenues, production, earnings or other results due to, among other reasons, the uncertainty of the underlying assumptions and estimates. However, in connection with EnLink’s evaluation of the Mergers, EnLink’s management provided to the EnLink Board, ONEOK and the EnLink Conflicts Committee’s financial advisor certain unaudited internal financial forecasts with respect to EnLink on a stand-alone basis prepared by EnLink’s management (the “EnLink Forecasted Financial Information”). The EnLink Forecasted Financial Information was provided by EnLink to Evercore for its use and reliance in connection with its financial analyses and opinion as described in the section entitled “The Mergers — Opinion of EnLink Conflicts Committee’s Financial Advisor.” The inclusion of this EnLink Forecasted Financial Information should not be regarded as an indication that any of EnLink, ONEOK, their respective affiliates, officers, directors, advisors or other representatives or any other recipient of this EnLink Forecasted Financial Information considered, or now considers, it to be necessarily predictive of actual future performance or events, or that it should be construed as financial guidance, and such projections set forth below should not be relied on as such.

The EnLink Forecasted Financial Information includes non-GAAP financial measures, including Adjusted EBITDA, Net Operating Income, Distributable Cash Flow, and Free Cash Flow After Distributions. Please see the tables below for a description of how EnLink defines these non-GAAP financial measures. EnLink believes that Adjusted EBITDA provides information useful in assessing operating and financial performance across periods, while Net Operating Income, Distributable Free Cash Flow and Free Cash Flow After Distributions each provides a useful measure of available cash generated by operating activities for other investing and financing activities. Non-GAAP financial measures should not be considered in isolation from, or as a substitute for, financial information presented in accordance with GAAP, and non-GAAP financial measures used by EnLink may not be comparable to similarly titled measures used by other companies.

This EnLink Forecasted Financial Information was prepared solely for internal use and is subjective in many respects. While presented with numeric specificity, the EnLink Forecasted Financial Information reflects numerous estimates and assumptions that are inherently uncertain and may be beyond the control of EnLink’s and ONEOK’s managements, including, among others, future results of EnLink, oil and gas industry activity, commodity prices, demand for natural gas and crude oil, general economic and regulatory conditions and other matters described in the sections entitled “Cautionary Statement Regarding Forward-Looking Statements” and “Risk Factors.” The EnLink Forecasted Financial Information reflects both assumptions as to certain business decisions that are subject to change and, in many respects, subjective judgment, and thus is susceptible to multiple interpretations and periodic revisions based on actual experience and business developments. Neither EnLink, ONEOK, nor their respective affiliates, officers, directors, advisors or other representatives can give assurance that the EnLink Forecasted Financial Information and the underlying estimates and assumptions will be realized. This EnLink Forecasted Financial Information constitutes “forward-looking statements” and actual results may differ materially and adversely from those set forth below.

The EnLink Forecasted Financial Information was not prepared with a view toward compliance with published guidelines of the SEC or the guidelines established by the American Institute of Certified Public Accountants for preparation or presentation of prospective financial information. The EnLink Forecasted Financial Information included in this proxy statement/prospectus has been prepared by, and is the responsibility of, management of EnLink. Neither KPMG LLP nor PricewaterhouseCoopers LLP has audited, reviewed, examined, compiled nor applied agreed-upon procedures with respect to the accompanying EnLink Forecasted Financial Information and,

accordingly, neither KPMG LLP nor PricewaterhouseCoopers LLP expresses an opinion or any other form of assurance with respect thereto. The report of KPMG LLP contained in EnLink’s Annual Report on Form 10-K for the year ended December 31, 2023, which is incorporated by reference into this proxy statement/prospectus, relates to historical financial information of EnLink, and such report does not extend to the EnLink Forecasted Financial Information and should not be read to do so. In addition, the PricewaterhouseCoopers LLP report contained in ONEOK’s Annual Report on Form 10-K for the year ended December 31, 2023, which is incorporated by reference in this proxy statement/prospectus, relates to ONEOK’s previously issued financial statements. Such report does not extend to the EnLink Forecasted Financial Information and should not be read to do so.

The EnLink Forecasted Financial Information does not take into account any circumstances or events occurring after the date it was prepared. Neither EnLink nor ONEOK can give assurance that, had the EnLink Forecasted Financial Information been prepared either as of the date of the Merger Agreement or as of the date of this proxy statement/prospectus, similar estimates and assumptions would be used. Except as required by applicable securities laws, EnLink and ONEOK do not intend to, and disclaim any obligation to, make publicly available any update or other revision to the EnLink Forecasted Financial Information to reflect circumstances existing since their preparation or to reflect the occurrence of unanticipated events, even if any or all of the underlying assumptions are shown to be inappropriate, including with respect to the accounting treatment of the Mergers under GAAP, or to reflect changes in general economic or industry conditions. The EnLink Forecasted Financial Information does not take into account all of the possible financial and other effects of the Mergers on EnLink, the effect on EnLink of any business or strategic decision or action that has been or will be taken as a result of the Merger Agreement having been executed, or the effect of any business or strategic decisions or actions that would likely have been taken if the Merger Agreement had not been executed, but which were instead altered, accelerated, postponed or not taken in anticipation of the Mergers. Further, the EnLink Forecasted Financial Information does not take into account the e