John Allen may refer to:

• John Allen (historian) (1771–1843), Scottish historian and political writer
• John Allen (bookseller) (1789–1829), English bookseller and antiquary
• John S. Allen (1907–1982), American university president

• John Allen (miner) (1775–?), English lead miner aboard HMS Investigator
• John Allen (trade unionist) (1804–1888), Irish trade union leader
• John Allen (saloon keeper) (1823–1870), American saloon keeper and underworld figure in New York City

• John Allen (soldier) (1771–1813), American Army officer killed in the War of 1812
• John Melville Allen (c. 1798–1847), American soldier; philhellene; first mayor of Galveston, Texas
• John Allen (Irish nationalist) (c. 1780–1855), Irish nationalist and colonel in the French army
• John Allen (RAF officer) (1916–1940), British flying ace of the Second World War
• John R. Allen Jr. (born 1935), United States Air Force general
• John R. Allen (born 1953), United States Marine Corps general
• John J. Allen (general), United States Air Force general

• John Allin (Puritan minister) (1596–1671), or Allen, English born Puritan cleric in Massachusetts
• John Allen (minister) (1741/2–1780s), English Baptist minister who supported the independence of America
• John Allen (religious writer) (1771–1839), English dissenting layman and religious writer
• John Allen (archdeacon of Chester) (died 1695)
• John Allen (archdeacon of Salop) (1810–1886), Welsh cleric
• John Allen (provost of Wakefield) (1932–2015), English Anglican Provost of Wakefield Cathedral
• John L. Allen Jr. (born 1965), American religion journalist

• John Allen (engineer) (born 1928), English engineer and plasma physicist
• John Allen (physician) (c. 1660–1741), English physician and inventor
• John F. Allen (biochemist) (born 1950), British biochemist
• John F. Allen (physicist) (Jack Allen, 1908–2001), Canadian physicist who worked on superfluid helium
• John P. Allen (born 1929), American ecologist and engineer; co-founder of the Biosphere 2 Center
• John R. L. Allen (1932–2020), British geologist
• John Romilly Allen (1847–1907), British archaeologist
• John T. Allen, Australian atmospheric scientist

• John Allen (baseball) (1890–1967), American baseball player
• Hap Allen (John Francis Allen Jr., 1900–1988), American baseball player
• John Allen (athlete) (1926–2006), American Olympic athlete
• John Allen (rugby union) (1942–2022), English rugby union player
• John Allen (footballer, born 1955), English footballer
• John Allen (hurler) (born 1955), English hurling player and manager
• John Allen (footballer, born 1964), English footballer for Chester City and Mansfield Town
• John Allen (American football) (fl. 1970s), American football coach
• John Allen (sportsman, born 1974), Australian rugby union player and cricketer
• John Allen (basketball) (born 1982), American basketball player
• John Allen (American football coach, SAGU) (born c. 1962), American football coach (SAGU 1996–1997)

• John Allen (settler) (1806–1879), English settler in the colony of Van Diemen's Land (later Tasmania)
• John Allen (pioneer) (1796–1851), American pioneer and co-founder of Ann Arbor, Michigan
• John C. Allen (1907–1979), American roller coaster designer
• John Whitby Allen (1913–1973), American pioneering model railroader
• John Allen (murderer) (1934–2015), English criminal who murdered his wife and children
• John P. Allen (musician), Canadian country, rock and bluegrass fiddler
• John Allen (guitarist), member of The Nashville Teens

• Allen (surname)
• Jack Allen (disambiguation)
• John Allan (disambiguation)
• Johnny Allen (disambiguation)
• Jon Allen (disambiguation)
• John Alen (1476–1534), English priest and canon lawyer
• John Alleyn (disambiguation), including John Alleyne
• John Allin (1921–1998), American Episcopalian bishop

This disambiguation page lists articles about people with the same name.
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