Material Event (Form 8-K)

This current report on Form 8-K is filed for the purpose of filing the attached exhibit in connection with the prospectus supplement, dated April 23, 2026 (the "Resale Prospectus Supplement"), filed by Capital One Financial Corporation (the "Company") with the Securities and Exchange Commission, which forms a part of the Company's automatic shelf registration statement on Form S-3 (File No. 333-277813).

The selling security holders referred to in the Resale Prospectus Supplement may offer and sell up to 10,345,906 shares of common stock, $0.01 par value per share, of the Company ("Company Common Stock") under the Resale Prospectus Supplement. The Company issued these shares of Company Common Stock to the selling security holders as consideration in connection with the Company's acquisition of Brex Inc., which closed on April 7, 2026.