John Cairns may refer to: John Cairns (biochemist) (1922–2018), biochemist who first demonstrated the structure and replication of the E. coli genome John Cairns (cricketer) (1925–2014), English cricketer John Cairns (politician) (1859–1923), British politician, MP for Morpeth John Cairns (1818–1892), Scottish divine and writer John Cairns (1857–1922), United Presbyterian Church minister, writer and biographer John Cairns (born 1942), former moderator of the general assembly of the Church of Scotland John Cairns (footballer) (1902–1965), Scottish football forward