William Fitzgerald or FitzGerald may refer to:
Law and politics United States William Fitzgerald (Tennessee politician) (1799–1864), U.S. representative from Tennessee William F. Fitzgerald (1846–1903), California attorney general and state Supreme Court justice William Henry Fitzgerald (1849–1922), Wisconsin state assemblyman William T. Fitzgerald (1858–1939), U.S. representative from Ohio William James Fitzgerald (Kansas politician) (1861–1937), lieutenant governor of Kansas William S. Fitzgerald (1880–1937), American politician William J. Fitzgerald (1887–1947), U.S. representative from Connecticut William H. G. FitzGerald (1909–2006), U.S. ambassador to Ireland William B. Fitzgerald (1914–1970), Michigan politician William B. Fitzgerald Jr. (1942–2008), American politician in Michigan
Elsewhere William FitzGerald, 2nd Duke of Leinster (1749–1804), Irish liberal politician and landowner Lord William FitzGerald (1793–1864), Irish politician William Patrick Fitzgerald (1864–1938), Australian politician William James Fitzgerald (jurist) (1894–1989), Irish jurist; chief justice of the Supreme Court of Palestine William FitzGerald (Irish judge) (1906–1974), Irish lawyer and judge
Religion William Fitzgerald (bishop of Clonfert and Kilmacduagh) (died 1722), Anglican bishop in Ireland William FitzGerald (bishop of Killaloe and Clonfert) (1814–1883), Irish Anglican bishop William Fitzgerald (bishop of Ross) (1832–1896), Irish Roman Catholic bishop
Sports Billy Fitzgerald (William James Fitzgerald, 1888–1926), Canadian field lacrosse player Bill Fitzgerald (hurler) (William Fitzgerald, 1892–1983), Irish hurler Will Fitzgerald (born 1999), Irish footballer
Others William FitzGerald, 13th Earl of Kildare (died 1599), Irish nobleman William Thomas Fitzgerald (1759–1829), British poet William FitzGerald-de Ros, 22nd Baron de Ros (1797–1874), British Lord and general William Fitzgerald (educationalist) (1838–1920), New Zealand teacher and educationalist William Vincent Fitzgerald (1867–1929), Australian botanist Nathan Boya, alias of William Fitzgerald (1924–2022), American daredevil William Charles Fitzgerald (1938–1967), United States Navy officer
See also William Vesey-Fitzgerald Bill Fitzgerald