John Thornton may refer to:
- John Thornton (MP) for Kingston-upon-Hull (UK Parliament constituency)
- John Thornton (glass painter) York Minster stain glass designer between 1405 and 1408
- John Thornton (American football) (born 1976), American football player
- John Thornton (Canadian politician) (1823–1888), merchant and politician in Quebec
- John Thornton (philanthropist) (1720–1790), merchant and Christian philanthropist
- John Thornton (Louisiana) (1846–1917), Louisiana politician and senator
- John Thornton (historian) (1949-), American historian
- John L. Thornton, former President and Co-COO of Goldman Sachs
- John Thornton (baseball), baseball pitcher
- John Thornton, a leading character in Jack London's novel Call of the Wild
- John Thornton (North and South), a leading character in Elizabeth Gaskell's novel North and South