William Hay
William Hay is the name of the following people:
- William Hay, 18th Earl of Erroll (1801–1846), British peer
- William Hay (architect) (1818–1888), Scottish architect
- William Hay (politician) (* 1950), Northern Irish politician
- William Perry Hay (1872-1947), American zoologist
- William Winn Hay (* 1934), American geologist
See also:
- Will Hay (1888–1949), British actor and astronomer
