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                                                                    EXHIBIT 23.1
 
               CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS
 
   
     We consent to the reference to our firm under the caption "Experts" in
Amendment No. 1 to the Registration Statement (Form S-4 No. 33-01997) and
related Prospectus of F.N.B. Corporation for the registration of 3,276,700
shares of its common stock and to the incorporation by reference therein of our
report dated February 5, 1996, with respect to the consolidated financial
statements of F.N.B. Corporation incorporated by reference in its Annual Report
(Form 10-K) for the year ended December 31, 1995, filed with the Securities and
Exchange Commission.
    
 
   
                                            /s/  ERNST & YOUNG, LLP
    
 
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                                          ERNST & YOUNG LLP
 
Pittsburgh, Pennsylvania
   
May 7, 1996