<TABLE> <S> <C>

<PAGE>
 
<ARTICLE> 9
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM PATAPSCO
BANCORP, INC. AND SUBSIDIARY AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO
SUCH FINANCIAL STATEMENTS.
</LEGEND>
       
<S>                             <C>                     <C>
<PERIOD-TYPE>                   6-MOS                   3-MOS
<FISCAL-YEAR-END>                          JUN-30-1997             JUN-30-1997
<PERIOD-START>                             JUL-01-1996             OCT-01-1996
<PERIOD-END>                               DEC-31-1996             DEC-31-1996
<CASH>                                       1,004,787               1,004,787
<INT-BEARING-DEPOSITS>                       6,641,005               6,641,005
<FED-FUNDS-SOLD>                             2,597,851               2,597,851
<TRADING-ASSETS>                                     0                       0
<INVESTMENTS-HELD-FOR-SALE>                          0                       0
<INVESTMENTS-CARRYING>                       9,907,739               9,907,739
<INVESTMENTS-MARKET>                         9,907,739               9,907,739
<LOANS>                                     56,568,797              56,568,797
<ALLOWANCE>                                    313,743                 313,743
<TOTAL-ASSETS>                              79,017,240              79,017,240
<DEPOSITS>                                  65,073,634              65,073,634
<SHORT-TERM>                                         0                       0
<LIABILITIES-OTHER>                          1,306,338               1,306,338
<LONG-TERM>                                          0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                         3,626                   3,626
<OTHER-SE>                                  12,633,642              12,633,642
<TOTAL-LIABILITIES-AND-EQUITY>              79,017,240              79,017,240
<INTEREST-LOAN>                              2,220,708               1,123,234
<INTEREST-INVEST>                              411,157                 176,568
<INTEREST-OTHER>                               231,591                 128,241
<INTEREST-TOTAL>                             2,863,456               1,428,043
<INTEREST-DEPOSIT>                           1,361,472                 679,999
<INTEREST-EXPENSE>                           1,361,472                 679,999
<INTEREST-INCOME-NET>                        1,501,984                 748,044
<LOAN-LOSSES>                                  120,000                  60,000
<SECURITIES-GAINS>                               1,844                       0
<EXPENSE-OTHER>                              1,512,084                 565,393
<INCOME-PRETAX>                               (13,648)                 186,285
<INCOME-PRE-EXTRAORDINARY>                    (13,648)                 186,285
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                   591,426                 114,310
<EPS-PRIMARY>                                     1.76                    0.34
<EPS-DILUTED>                                     1.76                    0.34
<YIELD-ACTUAL>                                    7.43                    7.42
<LOANS-NON>                                    579,000                 579,000
<LOANS-PAST>                                   579,000                 579,000
<LOANS-TROUBLED>                                     0                       0
<LOANS-PROBLEM>                                      0                       0
<ALLOWANCE-OPEN>                               219,001                 219,001
<CHARGE-OFFS>                                   26,146                  10,973
<RECOVERIES>                                       888                     250
<ALLOWANCE-CLOSE>                              313,743                 313,743
<ALLOWANCE-DOMESTIC>                                 0                       0
<ALLOWANCE-FOREIGN>                                  0                       0
<ALLOWANCE-UNALLOCATED>                              0                       0
        

</TABLE>