Material Event (Form 8-K)

Item 8.01. Other Events.

On January 21, 2026, T1 Energy Inc. (the "Company") filed with the Securities and Exchange Commission an automatic shelf registration statement on Form S-3ASR (File No. 333-292857) (the "Registration Statement"). On October 30, 2026, the Company filed a prospectus supplement (the "Resale Prospectus Supplement") pursuant to the Registration Statement covering the resale of shares of its common stock, par value $0.01 per share (the "common stock"), issuable upon conversion of the additional $50.0 million aggregate principal amount of the Company's 4.75% Convertible Senior Notes due 2031 (the "Convertible Notes") that were issued to the selling stockholder named in the Resale Prospectus Supplement the (the "Selling Stockholder") on September 30, 2026 under the indenture, dated as of July 31, 2026, between the Company and U.S. Bank Trust Company, National Association, as trustee. The shares of common stock registered for resale pursuant to the Resale Prospectus Supplement consist of 13,440,860 shares of common stock that may be issued to the Selling Stockholder upon the conversion of such Convertible Notes, assuming physical settlement will apply to all such conversions and including the maximum number of make-whole shares that may be issued pursuant to the terms of the Convertible Notes as described in the Resale Prospectus Supplement.

The filing of the Resale Prospectus Supplement is not itself a sale of securities by the Selling Stockholder and does not necessarily mean that the Convertible Notes held by the Selling Stockholder will be converted into shares of common stock or that the Selling Stockholder will choose to sell any shares of common stock. If any shares of common stock are sold by the Selling Stockholder, the Company would not receive any proceeds from that sale. No securities will be issued or sold by the Company pursuant to the Resale Prospectus Supplement.

The Company is filing this current report to provide the legal opinion as to the validity of the shares of common stock covered by the Resale Prospectus Supplement, which opinion is attached hereto as Exhibit 5.1 and is incorporated herein by reference.