John or Johnny Long may refer to:
Music John Long (blues musician) (born 1950), American country blues singer, fingerstyle guitarist, harmonica player and songwriter Johnny Long (musician) (1914–1972), American violinist and big band leader John Herbert Long (1904–1985), English music teacher and organist
Politics John Long (MP for Cricklade) (c. 1419–1478), English member of parliament (MP) for Cricklade John Long (16th-century MP) (c. 1517–c. 1600/1602), MP for Knaresborough, Hedon, Shaftesbury and Newcastle-under-Lyme John Long (Florida politician) (1946–2005), American politician from Florida John Long (North Carolina politician) (1785–1857), U.S. representative from North Carolina John Davis Long (1838–1915), governor of Massachusetts, later the U.S. Secretary of the Navy John B. Long (1843–1924), U.S. representative from Texas John Andrew Long (1869–1941), senator in Northern Ireland John David Long (1901–1967), South Carolina state senator John H. Long (political candidate) (fl. late 20th–early 21st centuries), Canadian political figure J. H. Long (John Henry Long, 1845–1898), American politician John V. Long (1826–1869), member of the Utah territorial legislature and clerk for Brigham Young
Science John Long (computer scientist) (1935–2025), British computer scientist John A. Long (born 1957), Australian paleontologist and author of children's books and popular science and adventure books John H. Long (chemist) (1856–1918), president of the American Chemical Society
Sports John Long (climber) (born 1953), American rock climber and writer John Long (basketball player) (born 1956), American basketball player Johnny Long (American football) (1914–1975), American football quarterback John Long (basketball coach), college men's basketball coach John Long (Australian footballer) (born 1946), Australian rules footballer John Long (Gaelic footballer) (born 1952), Irish Gaelic footballer
Other fields John Long (artist) (1964–2016), artist and painter from Northern Ireland John Long (evangelist) (1872–1962), Pentecostal preacher John Long (priest) (1913–2008), Anglican Archdeacon of Ely John Dixon Long (1817–1894), American abolitionist John Luther Long (1861–1927), American lawyer and writer whose short story "Madame Butterfly" inspired the opera by Puccini John Long (died 1935), founder of John Long Ltd, a now-defunct publishing firm based in London John F. Long (1920–2008), American real-estate developer, philanthropist John St. John Long (1798–1834), Irish–born quack doctor
See also John Longe (1548–1589), English Protestant archbishop of Armagh John Longe (priest) (1765–1834), priest and county magistrate