John Barrett
John Barrett or Johnny Barrett may refer to:
Clergy
- John Barrett (bishop), British clergyman who held high office in the Roman Catholic Church
- John Barrett (dean of Clonmacnoise), Irish Anglican priest
- John Barrett (Hebrew scholar), Irish Anglican priest
- John C. A. Barrett, Chairman of the World Methodist Council and educator
Military personnel
- John Barrett (Irish soldier), Irish colonel in the Williamite war
- John Barrett (Royal Navy officer), Irish captain in the Royal Navy
- John Cridlan Barrett, English recipient of the Victoria Cross
Politicians
- John Barrett (Australian politician), Australian senator
- John Barrett (Massachusetts politician), American legislator and former mayor of North Adams
- John Barrett (Missouri politician), American legislator
- John Barrett (Scottish politician), Scottish Liberal Democrat politician and the former Member of Parliament for Edinburgh West
- John Barrett Jr., Citizen Potawatomi Nation chairman
Scholars
- John Barrett (energy researcher), British energy and climate change scientist
- John Barrett (Hebrew scholar), Irish Anglican priest
- John C. Barrett, British archaeologist
- John W. Barrett (mathematician), British mathematician
- John W. Barrett (physicist), British mathematical physicist
Sportpeople
- John Barrett (American football), American football player
- John Barrett (athlete), Irish track and field athlete
- John Barrett (Australian footballer), Australian rules footballer
- John Barrett (cricketer), English cricketer
- John Barrett (ice hockey), Canadian NHL defenceman
- John Barrett (outfielder), American baseball outfielder
- John Barrett (tennis), English tennis player and commentator
- John Barrett (volleyball), Canadian volleyball player
- Johnny Barrett (American football), American football player
- Johnny Barrett (baseball), American baseball player
Others
- John Barrett (actor), British actor
- John Barrett (conservationist), British conservationist, author and broadcaster
- John Barrett (diplomat), United States ambassador to Siam, Argentina, Panama, and Colombia
- John Barrett (salon), the brand of beauty and hair salons by hairstylist John Barrett
- John Barrett, frontman of the band Bass Drum of Death
- John F. Barrett, CEO of Western & Southern Financial Group