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 May 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

Constellium SE (the “Company”) discloses voting results for proposals submitted at its Annual General Meeting of Shareholders held on May 2, 2024 (the “AGM”), with all the proposals passing, including the re-appointment of Jean-Christophe Deslarzes, Isabelle Boccon-Gibod and Jean-Philippe Puig to the Company’s Board of Directors for a period of three years following the AGM. The voting results will be posted on the Company’s website and are attached and incorporated herein by reference as Exhibit 99.1.

In addition, following their initial appointment as employee directors in 2021, both Jean-Francois Verdier and Wiebke Weiler have been re-appointed for an additional three-year term from the AGM to the annual general meeting to be held in 2027.

Following the AGM, the Company’s Board of Directors consists of: Mr. Jean-Christophe Deslarzes (Chair of the Board), Mr. Jean-Marc Germain (CEO), Mr. Emmanuel Blot, Ms. Isabelle Boccon-Gibod, Mr. Michiel Brandjes, Ms. Martha Brooks, Mr. John Ormerod, Mr. Jean-Philippe Puig, Mr. Jean-François Verdier, Ms. Lori A. Walker, and Ms. Wiebke Weiler.

The information contained in 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

CONSTELLIUM SE 2024 ANNUAL GENERAL MEETING VOTING RESULTS

Total Shares Outstanding: 145,832,473

Total Shares Voted: 127,155,122

Total % of Shares Voted: 87.19%