William Morgan may refer to:
United Kingdom
- William Morgan (died 1602), MP for Haslemere
- William Morgan (died 1569), MP for Monmouthshire
- William Morgan (died 1582), MP for Monmouthshire
- William Morgan (died 1583) (1542–1583), MP for Monmouth Boroughs
- William Morgan (of Tredegar) (1560–1653), Welsh politician
- William Morgan (of Rhymny), Welsh politician
- William Morgan (of Dderw) (died 1649), Welsh lawyer and politician
- William Morgan (of Machen and Tredegar) (c. 1640–1680), Member of Parliament for Monmouthshire 1659–1680
- Sir William Morgan (of Tredegar, elder) (1700–1731), Member of Parliament for Brecon, 1722–1723, and Monmouthshire, 1722–1731
- William Morgan (of Tredegar, younger) (1725–1763), Member of Parliament for Monmouthshire, 1747–1763
- William Morgan (abolitionist) (1815–c. 1890), town clerk in Birmingham, England
- William Pritchard Morgan (1844–1924), British Member of Parliament for Merthyr Tydfil, 1888–1900
- W. E. Morgan (William Evan Morgan, 1858–1916), Welsh trade union leader
- William James Morgan (1914–1999), Irish politician
United States
- William S. Morgan (1801–1878), U.S. Representative from Virginia
- William Duane Morgan (1817–1887), American newspaper editor and politician
- William Augustine Morgan (1831-1899), Virginia planter, Confederate cavalry officer, early West Virginia politician
- William J. Morgan (New York politician) (1840–1900), New York State comptroller, 1899–1900
- William Albert Morgan (1841–1917), Irish-American newspaper publisher and politician
- William Yoast Morgan (1866–1932), lieutenant governor of Kansas
- William McKendree Morgan (1869–1942), Idaho lawyer and politician
- William M. Morgan (congressman) (1870–1935), U.S. Representative from Ohio
- William J. Morgan (Wisconsin politician) (1883–1983), Wisconsin Attorney General
- William Fellowes Morgan Jr. (1889–1977), president of the Middle Atlantic Oyster Fisheries, and later Commissioner of Public Markets for New York City
- Will Morgan (born 1966), member of the Minnesota House of Representatives
- William Morgan (cricketer, born 1862) (1862–1914), Welsh cricketer
- William Morgan (cricketer, born 1864) (1864–1934), English cricketer
- William G. Morgan (1870–1942), American inventor of the game of volleyball
- William Llewellyn Morgan (1884–1960), Welsh international rugby union player
- William A. Morgan (footballer) (born 1914, date of death unknown), English footballer who played as goalkeeper for Coventry City F.C.
- William Morgan (rugby league), rugby league footballer of the 1930s for Wales, and Wigan
- Sack Morgan (William Lee Morgan), American baseball player
- William James Morgan aka Jimmy Morgan (1922–1975), English footballer and Royal Marines Commando
- Willie Morgan (born 1944), Scottish footballer
- William Morgan (judoka) (born 1975), Canadian Paralympic judo competitor