John Moffat may refer to:
- John Moffat (physicist) (born 1932), professor at the University of Toronto known for his work suggesting that the speed of light was much higher in the early universe
- John Smith Moffat (1835–1918), British missionary and imperial agent in southern Africa
- John Moffat (mining pioneer) (1841–1918), Scottish-born mining entrepreneur in Australia
- John Moffat (pilot) (born 1919), Royal Navy Fleet Air Arm pilot, famous for crippling the German battleship Bismarck