Jack Harkness is a character played by John Barrowman in Doctor Who and Torchwood.
Jack Harkness may also refer to:
- "Captain Jack Harkness" (Torchwood episode), an episode of Torchwood
- Jack Harkness, played by Matt Rippy, a minor Torchwood character
- Jack Harkness (footballer, born 1907) (1907–1985), Scottish footballer
- Jack Harkness (footballer, born 2004), Scottish footballer
- Jack Harkness (1918–1994), rose breeder with Harkness Roses