<TABLE> <S> <C>

<PAGE>
 
<ARTICLE> 9
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED STATEMENT OF CONDITION, THE CONSOLIDATED STATEMENT OF EARNINGS, THE
CONSOLIDATED STATEMENT OF CASH FLOWS, OF ITEM 8, AND TABLES 2, 16, 18 AND 19 OF
ITEM 7 OF THE AMSOUTH BANCORPORATION FORM 10-K FOR THE YEAR ENDED DECEMBER 31,
1998 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-START>                             JAN-01-1998
<PERIOD-END>                               DEC-31-1998
<CASH>                                         619,599
<INT-BEARING-DEPOSITS>                               0
<FED-FUNDS-SOLD>                                 5,609
<TRADING-ASSETS>                                 4,144
<INVESTMENTS-HELD-FOR-SALE>                  3,029,372
<INVESTMENTS-CARRYING>                       2,147,044
<INVESTMENTS-MARKET>                         2,162,102
<LOANS>                                     12,869,863
<ALLOWANCE>                                    176,075
<TOTAL-ASSETS>                              19,901,679
<DEPOSITS>                                  13,283,804
<SHORT-TERM>                                 1,570,973
<LIABILITIES-OTHER>                            379,514
<LONG-TERM>                                  3,239,759
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                       134,950
<OTHER-SE>                                   1,292,679
<TOTAL-LIABILITIES-AND-EQUITY>              19,901,679
<INTEREST-LOAN>                              1,085,846
<INTEREST-INVEST>                              370,534
<INTEREST-OTHER>                                 6,161
<INTEREST-TOTAL>                             1,462,541
<INTEREST-DEPOSIT>                             499,039
<INTEREST-EXPENSE>                             763,571
<INTEREST-INCOME-NET>                          698,970
<LOAN-LOSSES>                                   58,134
<SECURITIES-GAINS>                               8,336
<EXPENSE-OTHER>                                582,117
<INCOME-PRETAX>                                405,345
<INCOME-PRE-EXTRAORDINARY>                     405,345
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   262,712
<EPS-PRIMARY>                                     2.20
<EPS-DILUTED>                                     2.17
<YIELD-ACTUAL>                                    3.92
<LOANS-NON>                                     66,072
<LOANS-PAST>                                    23,832
<LOANS-TROUBLED>                                     0
<LOANS-PROBLEM>                                      0
<ALLOWANCE-OPEN>                               179,197
<CHARGE-OFFS>                                   69,265
<RECOVERIES>                                    22,909
<ALLOWANCE-CLOSE>                              176,075
<ALLOWANCE-DOMESTIC>                           133,840
<ALLOWANCE-FOREIGN>                                  0
<ALLOWANCE-UNALLOCATED>                         42,235
        

</TABLE>