John Buchanan, Canadian lawyer and politician, 20th Premier of Nova Scotia
John Buchanan may refer to:

In businessJohn Buchanan (oil executive) (1943–2015), New Zealand-born scientist and director

John C. Buchanan (businessman), businessman in 1840s San Francisco

John Murdoch Buchanan (1897–?), businessman and Chancellor of the University of British ColumbiaIn politics and lawJohn 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–?), 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), Virginia state senator, 1972–1991

John Hall 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 SenateIn religionJohn Buchanan (pastor), pastor of the Fourth Presbyterian Church of Chicago

John Buchanan (bishop), American bishop of the Episcopal ChurchIn sciences and medicineJohn 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 explorerIn sportsJohn 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 (soccer), former Canadian soccer coach, in Canadian Soccer Hall of FameIn other fieldsJohn Buchanan (inventor), Australian inventor of the atmospheric diving suit

John Buchanan (judoka) (born 1975), British judoka

John Buchanan (settler) (1855–1896), Scottish agriculturalist and early colonial settler in Nyasland

John Lee Buchanan (1831–1922), second president of Virginia Tech (then Virginia Agricultural and Mechanical College)