William Massey (disambiguation)
William Massey (1856–1925) was Prime Minister of New Zealand.
William Massey may also refer to:
- Bill Massey (baseball) (1871–1940), baseball player in 1894
- William Massey (cricketer) (1846–1899), played cricket for Somerset and Lancashire
- William Massey (rower) (1817–1898), rowed and played cricket for Cambridge University
- William A. Massey (1856–1914), U.S. Senator
- William A. Massey (mathematician), American mathematician
- William Nathaniel Massey (1809–1881), British author and politician
- William S. Massey (born 1920), American mathematician