John Barnett
John Barnett may refer to:
- John Barnett (Australian rules footballer), former Australian rules footballer
- John Barnett (composer), English composer
- John Barnett (rugby), Australian rugby union and rugby league player
- John Francis Barnett, English music composer and teacher
- John Davis Barnett, early Canadian curator-librarian
- Jack Barnett (baseball), American baseball player
- John Maughan Barnett, New Zealand organist, choirmaster and conductor
- John T. Barnett, American colonel
- John W. Barnett, American farmer, merchant and community leader
- John Manley Barnett, American conductor
- John Barnett (producer), New Zealand film and television producer
- John Barnett (whistleblower), Boeing whistleblower