Plains GP L P : Proxy Statement

April 14, 2023

Dear Fellow Plains Investors,

We are grateful for your investment in Plains, and we are pleased to invite you to join us for our May 24, 2023 annual meeting.

2022 represented a critical inflection point for Plains. We exited the year in a position of financial strength and well positioned to continue delivering strong operating and financial results. Throughout the year, we executed on our goals and initiatives in a dynamic macro environment.

Our integrated business model, flexible asset base and strong execution allowed us to capture increasing volumes from production growth and capitalize on commercial opportunities. As a result, we exceeded our financial guidance while also achieving record health, safety and environmental performance by meeting or exceeding 20% reduction targets in our key metrics. Overall achievements from 2022 include:

• Delivered $2.51 billion in Adjusted EBITDA attributable to PAA and Implied Distributable Cash Flow per Common Unit and Common Unit Equivalent of $2.26, exceeding our initial February targets of $2.2 billion and $2.00, respectively;
• Generated $1.61 billion in Free Cash Flow, returned approximately $658 million to common equity holders via distributions and unit repurchases, invested approximately $500 million of investment and maintenance capital, repaid $774 million of total debt and achieved a year-end leverage ratio (total debt/adjusted EBITDA) of 3.7x approximately one year earlier than originally planned;
• Completed and/or announced several win-win strategic transactions, all of which further optimized our asset base and streamlined our operations; and
• Announced multi-year capital allocation framework prioritizing Free Cash Flow generation, financial flexibility and targeting increasing return of capital to equity holders.

As we look ahead, we remain constructive on the long-term fundamentals that underpin our business and the need for North American energy, with recent events serving as a reminder that all forms of energy are needed to satisfy growing global energy demand. Underlying supply and demand fundamentals, together with realistic assumptions regarding the growth of various sources of energy, support our belief that hydrocarbons will remain an essential part of the world economy for decades to come. Energy from hydrocarbons will play a key role in supporting a growing global population, reducing poverty, extending longevity and improving overall quality of life.

With our network of strategically located North American midstream assets and our focus on the long-term positioning and optimization of our business, we believe we are very well positioned to play a critical role in the delivery of energy across North America and globally. As we do so, we will remain focused on generating meaningful multi-year free cash flow and maintaining a balanced approach to capital allocation that includes debt reduction and increasing returns of capital to equity holders through distribution increases and opportunistic repurchases. We believe the execution of our plan will deliver strong performance and enhanced value for our investors over the long term.

We appreciate your continued investment and support and we look forward to your participation in our 2023 annual meeting in May.

Sincerely,

Willie Chiang

Chairman of the Board & CEO

Plains GP Holdings, L.P.

333 Clay Street, Suite 1600

Houston, Texas 77002

NOTICE OF ANNUAL MEETING OF SHAREHOLDERS

To Be Held On May 24, 2023

To the holders of Class A, Class B and Class C shares of Plains GP Holdings, L.P.:

The 2023 Annual Meeting (the "PAGP Annual Meeting") of the Class A, Class B and Class C shareholders (collectively, our "Shareholders") of Plains GP Holdings, L.P. will be held on May 24, 2023, at 10:30 a.m. Central Time, in the Texas Room located on the 19th Floor of Three Allen Center, 333 Clay Street, Houston, Texas 77002. At the PAGP Annual Meeting, our Shareholders will consider and vote on the following matters:

1. The election of four Class I directors to serve on the board of directors (the "Board") of PAA GP Holdings LLC until the 2026 annual meeting;
2. The ratification of the appointment of PricewaterhouseCoopers LLP as our and Plains All American Pipeline, L.P.'s ("PAA") independent registered public accounting firm for the fiscal year ending December 31, 2023;
3. The approval, on a non-binding advisory basis, of our 2022 named executive officer compensation; and
4. Any proposal to transact such other business as may properly come before the PAGP Annual Meeting and any adjournment or postponement thereof.

The Board unanimously recommends that our Shareholders vote "FOR" proposals 1, 2 and

3. Additional information regarding these proposals is included in the attached proxy statement. See "Information About the PAA and PAGP Annual Meetings" below for more information.

Shareholders as of the close of business on March 27, 2023 (the "Record Date") are entitled to receive notice of and to vote at the PAGP Annual Meeting and any postponements or adjournments thereof. A list of Shareholders entitled to vote is on file at our principal offices, 333 Clay Street, Suite 1600, Houston, Texas 77002.

Your vote is very important. Whether or not you plan to attend the PAGP Annual Meeting, please cast your vote by following the Internet or telephone voting instructions on the proxy card. You may also vote by completing, signing and dating the accompanying proxy card and returning it promptly in the postage-prepaid envelope provided. See "Questions and Answers About the PAGP Annual

Meeting - How do I vote?" in the attached proxy statement for more details. Returning the proxy card or voting on the Internet or by telephone does not deprive you of your right to attend the PAGP Annual Meeting and to vote your shares for the matters to be acted upon at the PAGP Annual Meeting.

By Order of the Board of Directors of

PAA GP Holdings LLC, general partner of

Plains GP Holdings, L.P.

Richard McGee

Executive Vice President, General Counsel and Secretary

Houston, Texas

April 14, 2023

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF

PROXY MATERIALS FOR THE ANNUAL MEETING OF SHAREHOLDERS

TO BE HELD ON MAY 24, 2023

The Notice of Annual Meeting, the proxy statement for the Annual Meeting and our 2022 Annual

Report are available at http://www.astproxyportal.com/ast/21140/.

TABLE OF CONTENTS
GENERAL INFORMATION ABOUT THE PLAINS GP HOLDINGS, L.P. ANNUAL MEETING	1
INFORMATION ABOUT THE PAA AND PAGP ANNUAL MEETINGS	1
QUESTIONS AND ANSWERS ABOUT THE PAGP ANNUAL MEETING	1
CORPORATE GOVERNANCE AND RELATED MATTERS	7
PROPOSAL 1 - ELECTION OF CLASS I DIRECTORS	15
EXECUTIVE OFFICERS	26
EXECUTIVE COMPENSATION	28
SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT	66
EQUITY COMPENSATION PLAN INFORMATION TABLE	69
CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS	70
REPORT OF THE AUDIT COMMITTEE	74
PRINCIPAL ACCOUNTANT FEES AND SERVICES	75
PROPOSAL 2 - RATIFICATION OF APPOINTMENT OF INDEPENDENT REGISTERED PUBLIC
ACCOUNTING FIRM	76
PROPOSAL 3 - ADVISORY VOTE TO APPROVE OUR 2022 NAMED EXECUTIVE
OFFICER COMPENSATION	77
OTHER MATTERS FOR THE PAGP ANNUAL MEETING	78
DIRECTOR NOMINATIONS AND SHAREHOLDER PROPOSALS FOR THE 2024 ANNUAL
MEETING	78
HOUSEHOLDING MATTERS	79

i

PLAINS GP HOLDINGS, L.P.

PROXY STATEMENT

For

2023 Annual Meeting of Shareholders To Be Held On May 24, 2023

GENERAL INFORMATION ABOUT THE PLAINS GP HOLDINGS, L.P.

ANNUAL MEETING

The board of directors (the "Board") of PAA GP Holdings LLC ("PAGP GP" or our "general partner"), is soliciting proxies to be voted on behalf of our Class A, Class B and Class C shareholders (collectively, our "Shareholders") at the 2023 annual meeting of Shareholders (the "PAGP Annual Meeting"). This proxy statement is being furnished to you in connection with the solicitation of proxies by and on behalf of the Board for use at the PAGP Annual Meeting and includes information about the matters to be voted upon at the PAGP Annual Meeting. The PAGP Annual Meeting will be held on May 24, 2023, at 10:30 a.m. Central Time, in the Texas Room located on the 19th Floor of Three Allen Center, 333 Clay Street, Houston, Texas 77002. References to "PAGP," "we," "us," "our," "ours" and similar terms refer to Plains GP Holdings, L.P.

Proxy materials, including the Notice of Annual Meeting, this proxy statement, proxy card and our Annual Report on Form 10-K for the year ended December 31, 2022 (our "2022 Annual Report"), are being mailed to Shareholders beginning on or about April 14, 2023.

We will furnish additional copies of our 2022 Annual Report without charge upon the written request of any record or beneficial owner of our Class A, Class B or Class C shares whose proxy we are soliciting in connection with the PAGP Annual Meeting. Please address requests for additional copies of the 2022 Annual Report to the Investor Relations Department, Plains All American, 333 Clay Street, Suite 1600, Houston, Texas 77002, or email your request to [e-mail].

INFORMATION ABOUT THE PAA AND PAGP ANNUAL MEETINGS

At the PAGP Annual Meeting, our Class A, Class B and Class C shareholders will be asked to approve proposals 1, 2 and 3 described below. Each Shareholder will be entitled to one vote for each Class A, Class B and Class C share owned for Proposals 1, 2 and 3. Plains All American Pipeline, L.P. ("PAA") owns all of the issued and outstanding Class C shares, which serve as a pass-through voting mechanism allowing eligible PAA unitholders to vote indirectly at the PAGP Annual Meeting by instructing PAA how to vote the Class C shares on their behalf.

In order to obtain voting instructions from its eligible unitholders, PAA will hold an annual meeting (the "PAA Annual Meeting") immediately prior to the PAGP Annual Meeting. At the PAA Annual Meeting, PAA unitholders (other than Plains AAP, L.P. ("Plains AAP")) will vote on a pass-through basis on proposals 1, 2 and 3 described below by instructing PAA how to vote the PAGP Class C shares that it owns on such proposals at the PAGP Annual Meeting. PAA will vote (or refrain from voting) the Class C shares at the PAGP Annual Meeting on behalf of and according to the direction of PAA's unitholders (excluding Plains AAP) with respect to proposals 1, 2 and 3.

See pages 8-11 for additional information with respect to our ownership and voting structure.

QUESTIONS AND ANSWERS ABOUT THE PAGP ANNUAL MEETING

The following questions and answers are intended to briefly address some commonly asked questions regarding the PAGP Annual Meeting. These questions and answers may not address all questions that may be important to you as a Shareholder. Please refer to the additional information contained elsewhere in this proxy statement and the documents referred to in this proxy statement.

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