<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 NINE MONTHS
ENDED SEPTEMBER 30, 1999.
</LEGEND>
<MULTIPLIER> 1,000

<S>                             <C>
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-START>                             JAN-01-1999
<PERIOD-END>                               SEP-30-1999
<CASH>                                         584,176
<INT-BEARING-DEPOSITS>                               0
<FED-FUNDS-SOLD>                                22,625
<TRADING-ASSETS>                                 8,783
<INVESTMENTS-HELD-FOR-SALE>                  3,581,168
<INVESTMENTS-CARRYING>                       2,170,022
<INVESTMENTS-MARKET>                         2,126,990
<LOANS>                                     13,707,616
<ALLOWANCE>                                    177,556
<TOTAL-ASSETS>                              21,277,795
<DEPOSITS>                                  12,947,290
<SHORT-TERM>                                 2,260,183
<LIABILITIES-OTHER>                            358,977
<LONG-TERM>                                  4,238,887
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                       202,413
<OTHER-SE>                                   1,270,045
<TOTAL-LIABILITIES-AND-EQUITY>              21,277,795
<INTEREST-LOAN>                                837,013
<INTEREST-INVEST>                              264,231
<INTEREST-OTHER>                                 4,791
<INTEREST-TOTAL>                             1,106,035
<INTEREST-DEPOSIT>                             331,291
<INTEREST-EXPENSE>                             540,220
<INTEREST-INCOME-NET>                          565,815
<LOAN-LOSSES>                                   29,400
<SECURITIES-GAINS>                               8,860
<EXPENSE-OTHER>                                459,789
<INCOME-PRETAX>                                342,800
<INCOME-PRE-EXTRAORDINARY>                           0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   222,004
<EPS-BASIC>                                       1.26
<EPS-DILUTED>                                     1.25
<YIELD-ACTUAL>                                    4.08
<LOANS-NON>                                    106,072
<LOANS-PAST>                                    25,736
<LOANS-TROUBLED>                                     0
<LOANS-PROBLEM>                                      0
<ALLOWANCE-OPEN>                               176,075
<CHARGE-OFFS>                                   42,372
<RECOVERIES>                                    14,453
<ALLOWANCE-CLOSE>                              177,556
<ALLOWANCE-DOMESTIC>                                 0
<ALLOWANCE-FOREIGN>                                  0
<ALLOWANCE-UNALLOCATED>                              0


</TABLE>