William Mackenzie
William Mackenzie may refer to:
- William Mackenzie (ophthalmologist) (1791–1868), Scottish ophthalmologist
- William Mackenzie (contractor) (1794–1851), British civil engineering contractor
- William Lyon Mackenzie (1795–1861), Scottish-born journalist & rebel in Upper Canada; grandfather of Canadian prime minister William Lyon Mackenzie King
- William Mackenzie (railway entrepreneur) (1849–1923), railway contractor and entrepreneur in Canada, the United States, and Brazil
- William Douglas Mackenzie (1859–1936), American theologian
- William Mackenzie (publisher) (fl. 1870), Scottish publisher and printer
- Bill McKenzie, a former ice hockey player in the National Hockey League
- William McKenzie, Baron McKenzie of Luton (born 1946), English politician
- Will McKenzie (Inbetweeners), fictional character
- Will Mackenzie, American television director and actor
- Will MacKenzie, American golfer
- Billy Mackenzie, singer
- Billy MacKenzie (motorcyclist)
- Bill MacKenzie (born 1911), Canadian ice hockey player
- Bill McKenzie (born 1949), Canadian ice hockey player
- William McKenzie (Born 1980), Handbag Designer.