William Mellor could refer to:
Bill Mellor (1874–1940), American baseball player Bill Mellor (footballer), (1886–1938), English football goalkeeper Chip Mellor (full name William H. Mellor) (1950–2024), American lawyer and political activist Will Mellor (born 1976), (British actor) William Mellor (journalist) (1888–1942), British journalist and left-wing political activist William Mellor (footballer), English footballer William C. Mellor (1903–1963), American cinematographer William Frederick Mellor, English missionary
See also Billy Mellors, Scottish indoor and lawn bowler Jack Mellor (footballer, born 1896), English footballer John William Mellor (1835–1911), English lawyer Joseph William Mellor, English chemist