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