EXHIBIT 5


                                 June 11, 2003


Board of Directors
First Tennessee National Corporation
165 Madison Avenue
Memphis, TN 38103

Lady and Gentlemen:

         I have acted as counsel to First Tennessee National Corporation, a
Tennessee corporation (the "Company"), in connection with the registration on
Form S-8 (the "Registration Statement") under the Securities Act of 1933, as
amended (the "Act"), of deferred compensation obligations of the Company ( the
"Obligations") to be offered and sold pursuant to the terms of the First Horizon
Nonqualified Deferred Compensation Plan (the "Plan"). I have examined the
originals or copies, certified or otherwise identified to my satisfaction, of
such corporate records, certificates and other documents, and such questions of
law, as I have considered necessary or appropriate for the purposes of this
opinion.

         Upon the basis of such examination and subject to the limitations
contained herein, it is my opinion that the Plan has been duly adopted by the
Company and that the Obligations, when issued in accordance with the terms of
and subject to the conditions of the Plan, will be duly authorized and validly
issued and will constitute the valid and legally binding obligations of the
Company, enforceable against the Company in accordance with their terms and the
terms of the Plan, except as enforcement may be limited by (i) applicable
bankruptcy, insolvency (including, without limitation, all laws relating to
fraudulent transfers), moratorium, reorganization or other similar laws
affecting creditors' rights generally or (ii) general principles of equity,
regardless of whether such enforceability is considered in a proceeding in
equity or at law.

         The foregoing opinion is limited to the federal laws of the United
States and the laws of the State of Tennessee, and I am expressing no opinion as
to the effect of the laws of any other jurisdiction.



         In rendering the foregoing opinion, I have relied as to certain
matters, to the extent I deem such reliance appropriate, on statements,
representations and other information obtained from public officials, officers
of the Company and other sources believed by me to be responsible.

         I hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the reference to me in the Registration Statement.
In giving such consent, I do not thereby admit that I am in the category of
persons whose consent is required under Section 7 of the Act.


                                    Very truly yours,

                                    /s/ Clyde A. Billings, Jr.

                                    Clyde A. Billings, Jr.
                                    Senior Vice President, Assistant General
                                       Counsel and Corporate Secretary