__NOTOC__ William, Bill, Billy, Willie or Will Mackinnon, MacKinnon or McKinnon may refer to:
Politicians William Alexander Mackinnon (Dunwich MP) (1789–1870), British politician and South Australia colonisation commissioner William Alexander Mackinnon (Lymington MP) (1813–1903), British politician William S. McKinnon (1852–1908), American politician in Ohio William F. MacKinnon (1919–1990), Canadian politician Bill McKinnon (politician) (born 1933), Scottish-born Australian member of the Tasmanian House of Assembly
Military Sir William Alexander Mackinnon (British Army officer) (1830–1897), Director-General of British Army Medical Services Sir William Henry Mackinnon (1852–1929), British Army general
Sportsmen Billy MacKinnon (1852–1942), Scottish footballer for Queen's Park and Scotland national team in 1870s William McKinnon (footballer, born 1859) (1859–1899), Scottish footballer for Dumbarton and Scotland national team in 1880s Willie MacKinnon, American player in 1974 College Division East for Vermont Catamounts men's ice hockey#All-Americans Will MacKinnon, American gold medalist in Ice hockey at the 2016 Winter Youth Olympics#Events
Others Sir William Mackinnon, 1st Baronet (1823–1893), Scottish ship-owner and businessman , Uganda Railway Lake Victoria ferry named after him William MacKinnon (minister) (1843–1925), minister and Moderator of the Free Church of Scotland William McKinnon (police officer) (1902–1997), Australian police officer primarily within the Northern Territory Bill McKinnon (public servant) (1931–1988), Australian Secretary of Department of Immigration and Ethnic Affairs William P. MacKinnon (born 1939), American historian of Mormons and Utah