John Buchanan may refer to:
Business John Buchanan (oil executive) (1943–2015), New Zealand-born scientist and director John C. Buchanan (businessman) (fl. 1846–1848), businessman in San Francisco John Murdoch Buchanan (1897–1975), businessman and Chancellor of the University of British Columbia
Politics and law John Buchanan (Canadian politician) (1931–2019), premier of Nova Scotia, 1978–1990. John Buchanan (American politician), American journalist and U.S. presidential candidate, 2004 John Buchanan (Maryland judge) (1772–1844), chief judge of the Maryland Court of Appeals John Buchanan (MP) (1761–1839), Scottish politician, MP for Dunbartonshire 1821–26 John Buchanan (New Zealand politician) (1819–1892), New Zealand politician John A. Buchanan (1843–1921), US House of Representatives member from Virginia John Alexander Buchanan (1887–1976), Canadian senator John Andrew Buchanan (1863–1935), judge and politician in Astoria in the U.S. state of Oregon John C. Buchanan (Texas politician), Texas state senator, 1879–1885, see Eighteenth Texas Legislature John C. Buchanan (Virginia politician) (1911–1991), Virginia state senator, 1972–1991 John H. Buchanan Jr. (1928–2018), US House of Representatives member from Alabama John P. Buchanan (1847–1930), governor of Tennessee John Preston Buchanan (1888–1937), American politician in the Virginia Senate J. W. Buchanan (1871–1941), Arizona politician, state senator, state house of representatives
Religion John Buchanan (pastor) (1938–2025), pastor of the Fourth Presbyterian Church of Chicago John Buchanan (bishop) (1933–2020), American bishop of the Episcopal Church
Sciences and medicine John Buchanan (biologist) (1917–2007), professor of biochemistry at the Massachusetts Institute of Technology John Buchanan (botanist) (1819–1898), New Zealand botanist and scientific artist John Young Buchanan (1844–1925), Scottish chemist, oceanographer and Arctic explorer
Sports John Buchanan (English cricketer) (1887–1969), English cricketer and decorated WWI officer John Buchanan (Australian cricketer) (born 1953), Australian cricketer and coach John Buchanan (Cambuslang footballer) (fl. 1889), Scottish footballer John Buchanan (footballer, born 1899) (1899–1947), Scottish footballer (St Mirren, Rangers, Morton) John Buchanan (footballer, born 1928) (1928–2000), Scottish footballer (Clyde) John Buchanan (footballer, born 1935) (1935–2009), Scottish footballer (Hibernian) John Buchanan (footballer, born 1951), Scottish footballer (Cardiff City, Northampton Town) John Buchanan (sailor) (1884–1943), British Olympic gold medalist in 1908 John Buchanan (rugby union, born 1863) (1863–1933), Irish rugby union player Sir John Buchanan (rugby union, born 1896) (1896–1976), Scottish rugby union player and medical advisor John Buchanan (soccer), former Canadian soccer coach, in the Canadian Soccer Hall of Fame
Other fields John Buchanan (frontiersman) (1759–1832), American settler and founder of Buchanan's Station John Buchanan (inventor), Australian inventor of the atmospheric diving suit John Buchanan (judoka) (born 1975), British judoka John Buchanan (horticulturalist) (1855–1896), Scottish agriculturalist and early colonial settler in Nyasaland John Buchanan (Virginia colonist) (died 1769) Virginia landowner, magistrate and soldier John Lee Buchanan (1831–1922), second president of Virginia Tech (then Virginia Agricultural and Mechanical College) John Lanne Buchanan (fl. 1780–1816), Scottish author
See also James Buchanan (1791–1868), US president commonly misreferenced as "John"