UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 9)*

Hess Midstream LP

(Name of Issuer)

Class A Shares

(Title of Class of Securities)

428103105

(CUSIP Number)

Global Infrastructure Management LLC

Attention: Julie Ashworth

1345 Avenue of the Americas, 30^th Floor,

New York, New York 10105

(212) 315-8100

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

August 18, 2023

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), Rule 13d-1(f) or Rule 13d-1(g), check the following box.  ☐

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7(b) for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

Explanatory Note

This Amendment No. 9 to Schedule 13D amends and supplements the statement on Schedule 13D originally filed with the United States Securities and Exchange Commission on December 17, 2019 (as amended, the “Statement”), relating to the Class A Shares representing limited partner interests (the “Class A Shares”) of Hess Midstream LP, a Delaware limited partnership (the “Issuer”). Capitalized terms used herein without definition shall have the meaning set forth in the Statement.

Item 4 of the Statement is hereby amended and supplemented as follows:

August 2023 Option Exercise

On August 18, 2023, pursuant to the August 2023 Underwriting Agreement, the Underwriter exercised its option to purchase 1,500,000 Class A Shares from Blue Holding at $28.59 per share (the “August 2023 Option Exercise”). The August 2023 Option Exercise was consummated on August 22, 2023. In connection with the sale, Blue Holding redeemed 1,500,000 OpCo Class B Units for a corresponding number of Class A Shares.

Item 5 of the Statement is hereby amended and restated in its entirety as follows:

(a) – (b)

The following sets forth the aggregate number of Class A Shares and percentage of Class A Shares outstanding beneficially owned by each of the Reporting Persons, as well as the number of Class A Shares as to which each Reporting Person has the sole power to vote or to direct the vote, shared power to vote or to direct the vote, sole power to dispose or to direct the disposition of, or shared power to dispose or to direct the disposition of, as of the date hereof, based on 68,358,493 Class A Shares outstanding following the consummation of the August 2023 Option Exercise:

New HESM GP LP is the record holder of 898,000 Class A Shares. HIP GP LLC is the sole member of New HESM GP LLC, which is the general partner of New HESM GP LP. HIP GP LLC is a 50/50 joint venture between Hess Investments and Blue Holding. As such, each of the foregoing entities may be deemed to beneficially own the securities held of record by New HESM GP LP.

In addition, Blue Holding is the record holder of 76,556,634 Opco Class B Units, which may be redeemed for Class A Shares on a one-for-one basis at the option of the holder.

Blue Holding GP is the general partner of Blue Holding and Blue Holding Partnership. Global GP is the sole member of Blue Holding GP. Global Investors is the sole general partner of Global GP. As a result, each of Blue Holding GP, Global GP and Global Investors may be deemed to share beneficial ownership of the Opco Class B Units held of record by Blue Holding.

SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: August 22, 2023