Material Event (Form 8-K)

On December 23, 2025, KeyCorp (the "Company") filed a prospectus supplement to its Registration Statement on Form S-3 (No. 333-272573) (the "Registration Statement") filed with the U.S. Securities and Exchange Commission under the Securities Act of 1933, as amended, with respect to the registration of 161,968,762 common shares, par value $1.00 per share, of the Company that were issued to The Bank of Nova Scotia ("BNS") pursuant to the Investment Agreement, dated as of August 12, 2024, by and between the Company and BNS. Pursuant to the terms of the Investment Agreement, the Company was required to file this prospectus supplement no later than December 27, 2025.

In connection with the filing of the prospectus supplement, the Company is filing a legal opinion as Exhibit No. 5.1 to this Current Report on Form 8-K,which is incorporated by reference into the Registration Statement.