Exhibit 5.1 July 23, 2002 Board of Directors Capital One Financial Corporation 2980 Fairview Park Drive, Suite 1300 Falls Church, Virginia 22042 Gentlemen: As the General Counsel of Capital One Financial Corporation (the "Company"), I have participated in the preparation of a Registration Statement on Form S-8 to be filed with the Securities and Exchange Commission pursuant to the Securities Act of 1933, as amended (the "Registration Statement"), with respect to the registration of 3,000,000 shares of Common Stock, par value $.01 per share, of the Company to be issued pursuant to the Capital One Financial Corporation Associate Savings Plan (the "Plan"). I am familiar with the Registration Statement and have examined such corporate documents and records, including the Plan, and such matters of law as I have considered appropriate to enable me to render the following opinion. On the basis of the foregoing, I am of the opinion that the shares of Common Stock, when issued consistent with the terms of the Plan, will be binding obligations of the Company enforceable against the Company in accordance with their terms and conditions. I hereby consent to the filing of this opinion as Exhibit 5.1 to the Registration Statement and to the reference to me under the caption "Interests of Named Experts and Counsel" in the Registration Statement. Very truly yours, /s/ John G. Finneran, Jr. ----------------------------------------- John G. Finneran, Jr., Esq. Executive Vice President, General Counsel and Corporate Secretary