John Blyth, Blithe or Blythe may refer to:
Actors John Sidney Blyth (1882–1942), birth name of American actor John Barrymore John Blythe (actor) (1921–1993), English actor
Politicians John Blithe (MP) (before 1365 – 1410), English politician John Blythe (Jamaican politician) (died 1830s), member of the House of Assembly of Jamaica in 1820; father of John Buddle Blyth John Blythe (Canadian politician) (1842 – after 1890), Canadian politician
Religious figures John Blithe (priest) (before 1450 – after 1478), English Archdeacon of Stow and Lindsey 1477–78 John Blyth (bishop) (before 1460 – 1499), English Bishop of Salisbury 1493–99
Others John Buddle Blyth (1814–1871), Jamaican-born chemist, first professor of chemistry at Queen's College Cork in Ireland John Dean Blythe (1842–1869), English writer John Blythe (footballer) (1924–2007), English centre half
See also John Drew Barrymore or John Blyth Barrymore, Jr. (1932–2004), American actor, son of John Barrymore John Blyth Barrymore III (born 1954), American actor, son of John Drew Barrymore