Amentum Holdings Inc

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 (Amendment No. )

Filed by the Registrantþ

Filed by a Party other than the Registrant¨

Check the appropriate box:

¨Preliminary Proxy Statement

¨Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

þ Definitive Proxy Statement

¨Definitive Additional Materials

¨Soliciting Materials Pursuant to§240.14a-12

AMENTUM HOLDINGS, INC.

(Name of Registrant as Specified In Its Charter)

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

Payment of Filing Fee (Check the appropriate box):

þ No fee required.

¨Fee paid previously with preliminary materials.

¨Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

Notice of 2025

Annual Meeting

of Stockholders

and Proxy Statement

March 5, 2025

Amentum Holdings, Inc.

Dear Amentum Stockholder:

I would like to invite you to attend the first Annual Meeting of Stockholders of Amentum Holdings, Inc.

("Amentum" or the "Company"), to be held virtually at 11:00 a.m. (EST) on March 5, 2025 (the "Annual

Meeting"). A Notice of Internet Availability of Proxy Materials, which contains instructions on how to access

online our Proxy Statement and our Annual Report for the fiscal year ended September 27, 2024, is first being

sent to stockholders on or about January 21, 2025.

Items of business to be transacted at our Annual Meeting are:

1. Election of thirteen director nominees;

2. Ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm

for fiscal year 2025;

3. A non-binding, advisory vote on the compensation paid to the Company’s named executive officers in fiscal

year 2024, as disclosed in the proxy statement; and

4. A non-binding, advisory vote on the frequency of future advisory votes to approve named executive officer

compensation.

In addition to the foregoing, the Annual Meeting will include the transaction of such other business as may properly

come before the meeting, or any adjournment(s), continuation(s), rescheduling(s) or postponement(s) thereof.

The Board of Directors recommends that you vote “FOR” the nominees under Proposal 1, “FOR”

Proposals 2 and 3, and “ONE YEAR” for Proposal 4.

Our 2025 Annual Meeting of Stockholders will be a virtual meeting conducted solely online and can be attended

by visiting www.virtualshareholdermeeting.com/AMTM2025. To participate in the Annual Meeting, you will need

the control number located on your proxy card or the instructions that accompanied your proxy materials.

Your vote is important. You may vote by proxy online or by telephone. In addition, if you receive paper copies of

the proxy materials by mail, you may also vote by mail by following the instructions on the proxy card or voting

instruction form (if you hold your shares through a broker or bank). Voting online, by telephone, by written proxy

or by voting instruction form will ensure your representation at the Annual Meeting regardless of whether you

participate in the virtual meeting.

We look forward to your participation in our Annual Meeting. We appreciate your investment in and support of

Amentum.

Sincerely,

John Heller

Chief Executive Officer

NOTICE OF AMENTUM HOLDINGS, INC.'S 2025 ANNUAL

MEETING OF STOCKHOLDERS

*Our 2025 Annual Meeting of Stockholders will be a virtual meeting conducted solely online and can be

attended by visiting www.virt ualshareholdermeeting.com/AMTM2025. To participate in the Annual Meeting,

you will need the control number located on your proxy card or the instructions that accompanied your proxy

materials. If you plan to participate in the virtual meeting, please see “Important Information About Annual

Meeting and Proxy Procedures.”

On Behalf of the Board of Directors,

Paul W. Cobb, Jr.

Secretary

Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting of Stockholders

to be held on March 5, 2025: On January 21, 2025, we will begin mailing a notice, called the Notice of Internet

Availability of Proxy Materials (the “Notice”), to our stockholders advising them that this Proxy Statement, our

Annual Report on Form 10-K for the fiscal year ended September 27, 2024 and voting instructions can be

accessed over the Internet at www.proxyvote.com. You may then access these proxy materials online or you

may request that a printed copy of the materials be sent to you. If you want to receive a paper or e-mail copy of

these proxy materials, you may request one by telephone by calling 1-800-579-1639, online at

www.proxyvote.com or by e-mail to sendmaterial@proxyvote.com. If sending an email, please include your

control number (indicated on your Notice) in the subject line. There is no charge to you for requesting a copy.

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