Thomas Spencer may refer to:
- Thomas Spencer (minister) (1791–1811), English congregationalist
- Thomas Spencer (mathematical physicist) (born 1946), American mathematical physicist
- Thomas Edward Spencer (1845–1911), Australian writer
- Thomas Spencer (Marks and Spencer) (1852–1905), cashier
- Thomas Spencer (settler) (1607–1687), early settler of Hartford, Connecticut
- Sir Thomas Spencer, 3rd Baronet (1639–1685), politician
- Thomas Spencer (MP for Southwark), MP for Southwark, 1406–1415
- Thomas Spencer (cricketer) (1850–1933), English cricketer
- Sir Thomas Spencer, 1st Baronet (1586–1622), of the Spencer baronets
- Sir Thomas Spencer, 4th Baronet (died 1722) of the Spencer baronets
- W. Thomas Spencer (born 1928), American politician in the state of Florida
- Thomas Alfred Spencer (1860–1937), member of the Queensland Legislative Assembly