John Mann may refer to:

• John Mann (British actor), British radio actor
• John Mann (engineer), guitar engineer
• John Mann (musician) (1962–2019), Canadian folk-rock musician and actor
• Johnny Mann (1928–2014), American composer and recipient of multiple Grammy Awards

• John Mann (Australian cricketer) (1919–1969), Australian cricketer
• John Mann (English cricketer) (born 1983), English cricketer
• John Mann (water polo) (born 1985), American water polo player
• J. J. Mann (born 1991), American basketball player
• John Pelham Mann (1919–2002), English cricketer and British Army officer
• Johnny Mann (baseball) (1898–1977), American baseball player

• John Mann (Australian politician) (1869–1939), Australian politician
• John Mann, Baron Mann (born 1960), British politician
• John Mann (New Hampshire politician)

• John Frederick Mann (1819–1907), Australian surveyor and explorer

• Jackie Mann (1914–1995), British fighter pilot
• John Man (author) (born 1941), British author
• John Man (1512–1569), English churchman and diplomat
• Jonathan Mann (disambiguation)
• Mann (surname)