<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000276516
<NAME> Fidelity Money Market Trust
<SERIES>
<NUMBER> 51
<NAME> Retirement Government Money Market Portfolio
<MULTIPLIER> 1,000
<S>
<C>
<PERIOD-TYPE>
YEAR
<FISCAL-YEAR-END>
AUG-31-2000
<PERIOD-END>
AUG-31-2000
<INVESTMENTS-AT-COST>
4,577,948
<INVESTMENTS-AT-VALUE>
4,577,948
<RECEIVABLES>
52,264
<ASSETS-OTHER>
0
<OTHER-ITEMS-ASSETS>
0
<TOTAL-ASSETS>
4,630,212
<PAYABLE-FOR-SECURITIES>
35,069
<SENIOR-LONG-TERM-DEBT>
0
<OTHER-ITEMS-LIABILITIES>
24,128
<TOTAL-LIABILITIES>
59,197
<SENIOR-EQUITY>
0
<PAID-IN-CAPITAL-COMMON>
4,571,248
<SHARES-COMMON-STOCK>
4,571,151
<SHARES-COMMON-PRIOR>
4,199,083
<ACCUMULATED-NII-CURRENT>
0
<OVERDISTRIBUTION-NII>
0
<ACCUMULATED-NET-GAINS>
(233)
<OVERDISTRIBUTION-GAINS>
0
<ACCUM-APPREC-OR-DEPREC>
0
<NET-ASSETS>
4,571,015
<DIVIDEND-INCOME>
0
<INTEREST-INCOME>
261,215
<OTHER-INCOME>
0
<EXPENSES-NET>
16,928
<NET-INVESTMENT-INCOME>
244,287
<REALIZED-GAINS-CURRENT>
22
<APPREC-INCREASE-CURRENT>
0
<NET-CHANGE-FROM-OPS>
244,309
<EQUALIZATION>
0
<DISTRIBUTIONS-OF-INCOME>
244,287
<DISTRIBUTIONS-OF-GAINS>
0
<DISTRIBUTIONS-OTHER>
0
<NUMBER-OF-SHARES-SOLD>
7,826,729
<NUMBER-OF-SHARES-REDEEMED>
7,698,450
<SHARES-REINVESTED>
243,789
<NET-CHANGE-IN-ASSETS>
372,090
<ACCUMULATED-NII-PRIOR>
0
<ACCUMULATED-GAINS-PRIOR>
(256)
<OVERDISTRIB-NII-PRIOR>
0
<OVERDIST-NET-GAINS-PRIOR>
0
<GROSS-ADVISORY-FEES>
18,318
<INTEREST-EXPENSE>
5
<GROSS-EXPENSE>
18,337
<AVERAGE-NET-ASSETS>
4,364,654
<PER-SHARE-NAV-BEGIN>
1.000
<PER-SHARE-NII>
.056
<PER-SHARE-GAIN-APPREC>
0
<PER-SHARE-DIVIDEND>
.056
<PER-SHARE-DISTRIBUTIONS>
0
<RETURNS-OF-CAPITAL>
0
<PER-SHARE-NAV-END>
1.000
<EXPENSE-RATIO>
42
</TABLE>
