CSTM Constellium SE

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of August 2024

Commission File Number: 001-35931

Constellium SE

(Translation of registrant’s name into English)

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F ☒   Form 40-F ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): Yes ☐ No ☒

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): Yes ☐ No ☒

INFORMATION CONTAINED IN THIS FORM 6-K REPORT

Attached hereto as Exhibit 99.1 is a copy of a press release issued by Constellium SE (the “Company”) on August 27, 2024, regarding the appointment of Mr. Bradley L. Soultz as Special Advisor to the Board of Directors effective September 2024.

Exhibit Index

The information contained in Exhibit 99.1 of this Form 6-K, is incorporated by reference into any offering circular or registration statement (or into any prospectus that forms a part thereof) filed by Constellium SE with the Securities and Exchange Commission.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Exhibit 99.1

August 27, 2024

Constellium to Appoint Bradley L. Soultz as Special Advisor to the Board of Directors

Paris – Constellium SE (NYSE: CSTM) today announced that Mr. Bradley L. Soultz will be appointed as Special Advisor to the Board of Directors in September 2024. The Board expects to put forward the nomination of Mr. Soultz as a Non-Executive Director at the Company’s Annual General Meeting to be held in 2025.

Mr. Soultz has served as CEO of WillScot Mobile Mini (Nasdaq: WSC) since the merger of WillScot and Mobile Mini in 2020. Prior to becoming WillScot’s President and CEO in 2017, he served as President and CEO of Williams Scotsman (WSII), where he was responsible for the strategic and operational aspects of WSII’s North American business and for helping prepare the company for its reemergence as a public company.

Before joining WSII, Mr. Soultz worked for nine years at Novelis, most recently as Chief Commercial and Strategy Officer. He started his career with Cummins.

A U.S. national, Mr. Soultz has lived both in Europe and North America, and holds a Bachelor of Science Agricultural Engineering from Purdue University.

About Constellium

Constellium (NYSE: CSTM) is a global sector leader that develops innovative, value-added aluminium products for a broad scope of markets and applications, including aerospace, automotive and packaging. Constellium generated €7.2 billion of revenue in 2023.

www.constellium.com

1