<PAGE>

                                                                    EXHIBIT 31.1

                                 CERTIFICATIONS

I, Gary L. Tice, certify that:

      1.    I have reviewed this quarterly report on Form 10-Q of First National
            Bankshares of Florida, Inc.;

      2.    Based on my knowledge, this quarterly report does not contain any
            untrue statement of a material fact or omit to state a material fact
            necessary to make the statements made, in light of the circumstances
            under which such statements were made, not misleading with respect
            to the period covered by this quarterly report;

      3.    Based on my knowledge, the financial statements, and other financial
            information included in this quarterly report, fairly present in all
            material respects the financial condition, results of operations and
            cash flows of the registrant as of, and for, the periods presented
            in this quarterly report;

      4.    The registrant's other certifying officer and I are responsible for
            establishing and maintaining disclosure controls and procedures (as
            defined in Exchange Act Rules 13a-14 and 15d-14) for the registrant
            and we have:

                  a)    designed such disclosure controls and procedures to
                        ensure that material information relating to the
                        registrant, including its consolidated subsidiaries, is
                        made known to us by others within those entities,
                        particularly during the period in which this quarterly
                        report is being prepared;

                  b)    evaluated the effectiveness of the registrant's
                        disclosure controls and procedures as of a date within
                        90 days prior to the filing date of this quarterly
                        report (the "Evaluation Date"); and

                  c)    presented in this quarterly report our conclusions about
                        the effectiveness of the disclosure controls and
                        procedures based on our evaluation as of the Evaluation
                        Date;

      5.    The registrant's other certifying officer and I have disclosed,
            based on our most recent evaluation, to the registrant's auditors
            and the audit committee of registrant's board of directors (or
            persons performing the equivalent function):

                  a)    all significant deficiencies in the design or operation
                        of internal controls which could adversely affect the
                        registrant's ability to record, process, summarize and
                        report financial data and have identified for the
                        registrant's auditors any material weaknesses in
                        internal controls; and

                  b)    any fraud, whether or not material, that involves
                        management or other employees who have a significant
                        role in the registrant's internal controls; and

      6.    The registrant's other certifying officer and I have indicated in
            this quarterly report whether or not there were significant changes
            in internal controls or in other factors that could significantly
            affect internal controls subsequent to the date of our most recent
            evaluation, including any corrective actions with regard to
            significant deficiencies and material weaknesses.

Date: August 9, 2004

                                 /s/Gary L. Tice
                                 ---------------
                                 Gary L. Tice
                                 President and
                                   Chief Executive Officer