William Allan may refer to:
Politicians William Allan (banker) (c. 1770–1853), Canadian banker, businessman and politician William Allan (English politician) (1837–1903), Liberal Party politician in the United Kingdom William Allan (Queensland politician) (1840–1901), pastoralist and politician in Queensland, Australia
Sportspeople William Allan (footballer, born 1880) (1880–1965), Scottish goalkeeper for Falkirk, Rangers and Hibernian William Allan (footballer, born 1904) (1904–1969), Scottish defender for Hamilton and Motherwell Willie Allan (1942–2026), Scottish footballer Willie Allan (racing driver) (1930–2019), American dirt modified racing driver Bill Allan (1870–1948), Scottish footballer
Others William Allan (British Army officer) (1832–1918) William Allan (classicist) (born 1970), Scottish classicist William Allan (geneticist) (1881–1943), American physician and geneticist William Allan (painter) (1782–1850), Scottish historical painter William Allan (trade unionist) (1813–1874), British trade unionist William Evan Allan (1899–2005), Australian military figure, seeing service in WWI and WWII William Allan of Glen (1788–1868), Lord Provost of Edinburgh
See also Bill Allen (disambiguation) Will Allen (disambiguation) William Allen (disambiguation) William FitzAlan, Lord of Oswestry (c. 1105–1160), Norman noble William Van Alen (1883–1954), American architect Norman Allan (Norman Thomas William Allan, known as Bill), former Australian (N.S.W.) police commissioner George William Allan (1822–1901), Canadian politician George William Allan (Manitoba politician) (1860–1940), Canadian politician