William Spencer
William Spencer is the name of the following people:
- William Spencer, 2nd Baron Spencer of Wormleighton (1591–1636), English nobleman and politician
- William Spencer (cyclist) (1895–1963), American cyclist
- William Spencer (track and field athlete) (1900-1983), American track and field athlete
- William Allen Spencer (* 1936), American biathlete, see Bill Spencer
- William B. Spencer (1835–1882), American politician
- William Browning Spencer (born 1946), American writer
- William O'Neill Spencer (1909–1944), American jazz drummer and singer, see O'Neill Spencer
- William Robert Spencer (1769–1834), English poet and translator