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
- William McKenzie, Baron McKenzie of Luton (born 1946), English politician
- William Mackenzie, 1st Baron Amulree (1860–1942), British barrister, public servant and politician
- William Alexander McKenzie (1874–1966), builder and political figure in British Columbia
- William Colin Mackenzie (1877–1938), Australian anatomist, benefactor, museum administrator and director
- William Forbes Mackenzie (1807–1862), Scottish Conservative politician and temperance reformer
- William Mackay Mackenzie (1871–1952), Scottish historian, archaeologist and writer
- William Mackenzie, 5th Earl of Seaforth (died 1740), Scottish nobleman
- Will McKenzie (Inbetweeners), fictional character
- Will Mackenzie (born 1938), American television director and actor
- Will MacKenzie (born 1974), American golfer
- Billy Mackenzie (1957–1997), singer
- Billy MacKenzie (motorcyclist) (born 1984), Scottish motocross racer
- Bill MacKenzie (1911–1990), Canadian ice hockey player
- Bill McKenzie (born 1949), Canadian ice hockey player
Famous quotes containing the word mackenzie:
“Rarely do American parents deliberately teach their children to hate members of another racial, religious, or nationality group. Many parents, however, communicate the prevailing racial attitudes to their children in subtle and sometimes unconscious ways.”
—Kenneth MacKenzie Clark (20th century)