<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 1 of Part I and tables 2, 6 and 7
of Item 2 of Part I of the AmSouth Bancorporation Form 10-Q for the quarterly
period ended March 31, 1998 and is qualified in its entirety by reference to
such financial statements.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-START>                             JAN-01-1998
<PERIOD-END>                               MAR-31-1998
<CASH>                                         604,244
<INT-BEARING-DEPOSITS>                               0
<FED-FUNDS-SOLD>                                   825
<TRADING-ASSETS>                                 1,194
<INVESTMENTS-HELD-FOR-SALE>                  3,049,531
<INVESTMENTS-CARRYING>                       2,480,571
<INVESTMENTS-MARKET>                         2,493,889
<LOANS>                                     12,206,942
<ALLOWANCE>                                    179,347
<TOTAL-ASSETS>                              19,390,061
<DEPOSITS>                                  12,989,728
<SHORT-TERM>                                 1,778,919
<LIABILITIES-OTHER>                            317,521
<LONG-TERM>                                  2,877,463
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                       134,996 <F1>
<OTHER-SE>                                   1,291,434 <F1>
<TOTAL-LIABILITIES-AND-EQUITY>              19,390,061
<INTEREST-LOAN>                                264,733
<INTEREST-INVEST>                               89,498
<INTEREST-OTHER>                                 1,251
<INTEREST-TOTAL>                               355,482
<INTEREST-DEPOSIT>                             123,097
<INTEREST-EXPENSE>                             183,815
<INTEREST-INCOME-NET>                          171,667
<LOAN-LOSSES>                                   14,400
<SECURITIES-GAINS>                               1,743
<EXPENSE-OTHER>                                136,914
<INCOME-PRETAX>                                 96,158
<INCOME-PRE-EXTRAORDINARY>                      96,158
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    62,023
<EPS-PRIMARY>                                      .51 <F1>
<EPS-DILUTED>                                      .51 <F1>
<YIELD-ACTUAL>                                    4.04
<LOANS-NON>                                     88,760
<LOANS-PAST>                                    32,363
<LOANS-TROUBLED>                                     0
<LOANS-PROBLEM>                                      0
<ALLOWANCE-OPEN>                               179,197
<CHARGE-OFFS>                                   20,880
<RECOVERIES>                                     6,630
<ALLOWANCE-CLOSE>                              179,347
<ALLOWANCE-DOMESTIC>                                 0
<ALLOWANCE-FOREIGN>                                  0
<ALLOWANCE-UNALLOCATED>                              0
<FN>
<F1> All common stock and per share amounts reflect a three-for-two stock
split payable April 30, 1998. Prior financial data schedules have not been 
adjusted to reflect this split.
</FN>
        

</TABLE>