As filed with the Securities and Exchange Commission on May 26, 2021

Registration No. 333-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

PLAINS ALL AMERICAN PIPELINE, L.P.

(Exact name of registrant as specified in its charter)

PLAINS ALL AMERICAN 2021 Long-Term Incentive Plan

(Full title of the plan)

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”).

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act of 1933, as amended (the “Securities Act”).     ¨

CALCULATION OF REGISTRATION FEE

EXPLANATORY NOTE AND STATEMENT OF INCORPORATION BY REFERENCE

The Registrant previously filed the following registration statements on Form S-8 with the Securities and Exchange Commission (the “Commission”): (i) on February 14, 2005 registering 6,000,000 Common Units in connection with the Plains All American 2005 Long-Term Incentive Plan (File No. 333-122806); (ii) on November 17, 1999 registering 1,950,000 Common Units in connection with the Plains All American GP LLC 1998 Long-Term Incentive Plan (File No. 333-91141); (iii) on December 11, 2001 registering 900,000 additional Common Units in connection with the Plains All American GP LLC 1998 Long-Term Incentive Plan (File No. 333-74920); (iv) on March 9, 2007 registering 1,999,618 Common Units in connection with the Plains All American PPX Successor Long-Term Incentive Plan (File No. 333-141185); and (v) on December 31, 2013 registering 7,000,000 Common Units in connection with the Plains All American 2013 Long-Term Incentive Plan (collectively, the “Prior Registration Statements”).

At the PAA 2021 Annual Meeting held on May 19, 2021, the Registrant’s unitholders approved the Plan, which is an amendment, restatement and renaming of the Plains All American 2013 Long-Term Incentive Plan (which was an amendment and restatement of the Plains All American 2005 Long-Term Incentive Plan, the Plains All American GP LLC 1998 Long-Term Incentive Plan and the Plains All American PPX Successor Long-Term Incentive Plan), and authorized an incremental 20,000,000 Common Units that may be used for awards under the Plan. This Registration Statement is being filed in accordance with General Instruction E of Form S-8 for the purpose of registering the issuance of an additional 20,000,000 Common Units under the Plan.

As permitted by General Instruction E of Form S-8, the contents of the Prior Registrations are hereby incorporated by reference into this Registration Statement.

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Except to the extent that information is deemed furnished and not filed pursuant to securities laws and regulations, the Registrant hereby incorporates by reference into this Registration Statement the following documents:

Except to the extent that information is deemed furnished and not filed pursuant to securities laws and regulations, all documents filed by the Registrant pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the date hereof and prior to the filing of a post-effective amendment that indicates that all securities offered have been sold or that deregisters all securities then remaining unsold shall also be deemed to be incorporated by reference herein and to be a part hereof from the dates of filing of such documents. Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein or in any other subsequently filed document which also is or is deemed to be incorporated by reference herein modifies or supersedes such statement. Any statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement.

*           Filed herewith.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Houston, State of Texas, on May 26, 2021.

POWER OF ATTORNEY

Each person whose signature appears below appoints Al Swanson and Richard McGee, and each of them, either of whom may act without the joinder of the other, as his true and lawful attorneys-in-fact and agent, with full power of substitution and re-substitution, for him and in his name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement and any Registration Statement (including any amendment thereto) for this offering that is to be effective upon filing pursuant to Rule 462(b) under the Securities Act of 1933, as amended, and to file the same, with all exhibits thereto, and all other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agent full power and authority to do and perform each and every act and thing requisite and necessary to be done, as fully to all intents and purposes as he might or would do in person, hereby ratifying and confirming all that said attorneys-in-fact and agent may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed below by the following persons in the capacities and the dates indicated.