William Mills may refer to:
Politics William Mills (1750–1820), MP for St Ives 1790–96 and Coventry 1805–12 William J. Mills (1849–1915), governor of the New Mexico Territory William George Mills (1859–1933), sheep breeder and politician in South Australia William Oswald Mills (1924–1973), American politician William Thomas Mills (1924–2011), merchant and politician in Ontario, Canada William Stratton Mills (born 1932), politician in Northern Ireland William Mills (Lord Provost) (1776–1857), Scottish cotton merchant and lord provost of Glasgow William Ellison Mills (1859–1930), American leather manufacturer and politician from New York William Fitz Randolph Mills (1856–1941), mayor of Denver, Colorado
Sports William Mills (English cricketer) (1820–1877), English lawyer and cricketer William Mills (New Zealand cricketer) (1875–1962), New Zealand cricketer William Mills (rugby union), English international rugby union player Willie Mills (baseball) (1877–1933), American professional baseball pitcher Billy Mills (footballer) (1891–19???), English professional footballer Billy Mills (racing driver) (1898–1937), South African racing driver Willie Mills (1915–1991), Scottish professional footballer Bill Mills (baseball) (1919–2019), Major League Baseball player Billy Mills (born 1938), American Olympic athlete
Others William Mills (actor) (1701–1750), British stage actor William Augustus Mills (1777–1844), American major general in the War of 1812 William Mills (surveyor) (1844–1916), Australian surveyor William Mills (bishop) (1846–1917), Canadian Anglican bishop of Ontario William Mills (inventor) (1856–1932), inventor of the Mills bomb William Corless Mills (1860–1928), American museum curator William Mills (businessman) (1866–1916), Western Australian businessman William Hobson Mills (1873–1959), British organic chemist William Harold Mills (1921–2007), American mathematician Billy G. Mills (born 1929), Los Angeles Superior Court judge and City Council member Billy Mills (poet) (born 1954), Irish poet Robert William Mills (1777–1851), English politician William Hemingway Mills (1834–1918), British civil engineer