William Caldwell may refer to:
Military William Caldwell (ranger) (c. 1750–1822), Irish-Canadian soldier in the American Revolution and War of 1812 William B. Caldwell III (1925–2013), U.S. Army general William B. Caldwell IV (born 1954), U.S. Army general, son of William B. Caldwell III
Law William B. Caldwell (judge) (1808–1876), American judge William W. Caldwell (1925–2019), American federal judge
Politics William Caldwell (Illinois politician), 19th century Illinois state representative William Caldwell (Nova Scotia politician) (1793–1854), mayor of Halifax, Nova Scotia William Caldwell (Wisconsin politician), member of the 1st Wisconsin legislature of 1848 William Bletterman Caldwell (1798–1892), governor of the Red River Settlement William Clyde Caldwell (1843–1905), Ontario businessman and politician William Murray Caldwell (1832–1870), New Brunswick businessman and political figure William Parker Caldwell (1832–1903), member of the United States House of Representatives
Other fields William Caldwell (Royal Navy officer), (died 1718), British admiral William Caldwell (hymnist) (1801–1857), who compiled a hymn and tune book Union Harmony William Caldwell (cricketer) (1878–1964), English cricketer William A. Caldwell (1906–1986), American journalist and columnist William Hay Caldwell (1859–1941), Scottish biologist William S. Caldwell (1821–1874), American philanthropist. Bill Caldwell (American football), American football player and coach
See also Acer campestre 'William Caldwell', a field maple cultivar named for the eponymous nurseryman Bill Caldwell (racing driver), New Zealand racing driver in 1966 Tasman Series Billy Caldwell (1782–1841), Potawatomi leader Will Caldwell (born 1982), Australian rugby union player Willie Walker Caldwell (1860–1946), American writer and club woman