CONSTELLIUM SE

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2025

OR

For the transition period from _________ to __________

Commission file number:001-35931

Constellium SE

(Exact name of registrant as specified in its charter)

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☑ No ☐

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ☐No ☑

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during

the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for

the past 90 days. Yes ☑ No ☐

Indicate by check mark whether the registrant submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation

S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☑ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or 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 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 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control

over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its

audit report.☑

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing

reflect the correction of an error to previously issued financial statements.☑

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by

any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).☑

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐No☑

The aggregate market value of the registrant’s ordinary shares held by non-affiliates of the registrant as of the last business day of the registrant’s most recently

completed second fiscal quarter (June 30,2025) was approximately$1.8 billion.

The number of outstanding ordinary shares of the registrant on January 30, 2026, was 135,069,771 shares.

Documents Incorporated By Reference

Portions of the registrant’s proxy statement for its 2026 Annual Meeting of Stockholders to be filed within 120 days after the close of the registrant’s fiscal year

are incorporated by reference into Part III of this Annual Report on Form 10-K.

Table of Contents

Forward-Looking Statements

This Annual Report on Form 10-K contains “forward-looking statements” within the meaning of the Private Securities

Litigation Reform Act of 1995. You can identify certain forward-looking statements because they contain words such as, but

not limited to, “anticipates,” “believes,” “could,” ”estimates,” “expects,” “forecasts,” “intends,” “likely,” “may,” “plans,”

“should,” “targets,” “will,” or “would,” and similar expressions (or the negative of these terminologies or expressions).

Forward-looking statements do not relate strictly to historical or current facts and reflect management’s current assumptions,

beliefs, expectations, objectives, plans and projections about the future, including with respect to our business, results of

operations and financial condition. Accordingly, forward-looking statements are subject to uncertainties, risks and changes that

are difficult to predict and many of which are outside of our control. Such factors include, but are not limited to, those described

in “Part I, Item 1A. Risk Factors” and “Part II, Item 7. Management’s Discussion and Analysis of Financial Condition and

Results of Operations.” If underlying assumptions prove inaccurate, or known or unknown risks or uncertainties materialize,

actual results could vary materially from expectations expressed or implied in the forward-looking statements. Investors are

cautioned not to place undue reliance on any such forward-looking statements, which speak only as of the date they are made.

We undertake no obligation to update any forward-looking statement, whether because of new information, future events or

otherwise, except as required by law.