William Thompson may refer to:
- William Thompson (general) (1736–1781), American Revolutionary War general
- William Thompson (Medal of Honor, 1861) (1812–1872), signal quartermaster in the American Civil War
- William P. Thompson (1844–1864), American Civil War recipient of the Medal of Honor
- William Francis Kynaston Thompson (1909–1980), British officer who fought and was captured at Arnhem
- William Thompson (admiral) (1922–2018), American admiral, former chief of the U.S. Navy Memorial Foundation
- William Thompson (Medal of Honor, 1950) (1927–1950), Korean War recipient of the Medal of Honor
- Frank Thompson (SOE officer) (William Frank Thompson, 1920–1944), British officer who worked in Bulgaria in the Second World War
- James Thompson (VC) (William James Thompson, 1830–1891), English recipient of the Victoria Cross
U.S.
- William Thompson (North Carolina politician) (1772–1802), member of the North Carolina General Assembly
- William B. Thompson (1797–?), Virginia farmer and politician
- William Thompson (Iowa politician) (1813–1897), representative from Iowa
- William C. Thompson (New York), lawyer and state senator
- William F. Thompson (1852–?), representative from Florida
- William George Thompson (1830–1911), representative from Iowa
- William G. Thompson (1840–1904), mayor of Detroit
- William Henry Thompson (1853–1937), senator from Nebraska
- William I. S. Thompson (1936–1993), member of the Mississippi House of Representatives
- William Barlum Thompson (1860–1941), mayor of Detroit
- William T. Thompson (Nebraska politician) (1860–1939), Nebraska Attorney General and Solicitor of the United States Treasury
- William Hale Thompson (1868–1944), mayor of Chicago
- William Howard Thompson (1871–1928), senator from Kansas
- W. Lair Thompson (1880–1940), American politician and lawyer from the state of Oregon
- William Carrington Thompson (1915–2011), American politician and jurist from Virginia
- William Thompson (New York) (born 1953), New York City Comptroller and Democratic nominee for mayor of New York City
- Bill Thompson (Arkansas politician), a state legislator in Arkansas
U.K.
- William Thompson (died 1637), MP for Scarborough
- William Thompson (1614–1681), English Member of Parliament for the City of London
- William Thompson (1629–1692), English Member of Parliament for Scarborough
- William Thompson (Ipswich MP) (1678–1739), English Member of Parliament for Ipswich
- William Thompson (died 1744) (c.1680–1744), British Whig politician, MP for Scarborough 1701–1722 and 1730–1744
- William Thompson (1792–1854), MP for Callington, London, Sunderland and Westmorland, also Sheriff and Lord Mayor of London
- William Thompson (Ulster Unionist politician) (1939–2010), Northern Ireland politician
- William Thompson (naturalist) (1805–1852), Irish ornithologist and botanist
- William Thompson (viticulturist) (1816–1897), Englishman who developed the Thompson Seedless grape
- William Wardlaw Thompson (died 1917), South African ichthyologist and zoologist
- William Thompson (physician) (1861–1926), physician, Registrar General for Ireland
- William A. Thompson (1864–1925), member of the U.S Army Corps of Engineers
- William B. Thompson (1922–1995), British plasma physicist
- William Boyce Thompson (1869–1930), American mining engineer and financier
- William R. Thompson (1887–1972), Canadian entomologist
- William Francis Thompson (biologist) (1888–1965), American ichthyologist
- William Lay Thompson (1930–2016), American ornithologist
- William Thompson (boxer) (1811–1880), British prizefighter
- William Thompson (archer) (1848–1918), American archer
- William V. Thompson (1865–1938), American bowler
- William Thompson (cricketer, born 1866) (1866–1920), English first-class cricketer
- Willie Thompson (William Pringle Thompson, 1867–1928), English footballer, played for Newcastle United in the 1890s
- William Thompson (cricketer, born 1882) (1882–1954), English cricketer
- William Thompson (Australian cricketer) (born 1891, date of death unknown), Australian cricketer
- William Thompson (British Guiana cricketer) (born 1888, date of death unknown), Guyanese cricketer
- William Thompson (rower) (1908–1956), American Olympic rower
- William Thompson (footballer), Scottish footballer
- William Thompson (skier) (1905–1994), Canadian Olympic skier
- Will Thompson (baseball) (1870–1962), American baseball player
- William Thompson (banker), Governor of the Bank of England from 1725 to 1727
- William Thompson (Methodist) (1733–1799), first President of the Methodist Conference after Wesley's death
- William Thompson (philosopher) (1775–1833), Irish political and philosophical writer and social reformer
- William Thompson (journalist) (1846–1934), American Indian fighter and newspaper editor
- William Clyde Thompson (1839–1912), leader of the Mount Tabor Indian Community in Texas
- William Thompson (bishop) (1885–1975), Anglican bishop of Persia (Iran)
- William A. Thompson (bishop) (1946-2020), Anglican bishop of the Diocese of Western Anglicans (U.S.)
- William Thompson (archdeacon of Cork) (1766–1833)
- William Thompson (archdeacon of Wellington), Canadian Anglican priest
- William C. Thompson (New York judge) (1924–2018), New York politician and judge
- William Paul Thompson (1937–1989), American serial killer
- William L. ("T") Thompson (born 1951), pilot for Delta Air Lines, lawyer, and businessman
- William C. Thompson (Alabama judge) (born 1962), judge on the Alabama Court of Civil Appeals
- William Harvey Thompson (died 1927), prohibition enforcement agent in Seattle, Washington
- William Thompson (confidence man), American criminal
- William S. Thompson, American judge in West Virginia
- William Thompson (pirate), ship captain who stole the Treasure of Lima c. 1820
- William Francis Thompson (1810-42), civil servant, magistrate and philatelist
- William Thompson (1805–1866), also known as Wiremu Tamihana, Maori preacher