John Duggan
John Duggan may refer to:
- John Duggan (rugby, born 1929), English former rugby union and rugby league footballer
- John Duggan (rugby union, born 1948), Irish former Leicester Tigers winger
- John Duggan (bishop), Bishop of Tuam, Killala, and Achonry, 1970–1985
- Jack Duggan (politician), Australian politician for Electoral district of Toowoomba West
- Johnny Duggan (jockey), on racehorse Gold and Black
- John Duggan, main character in the TV series Duggan
- John Duggan, character in the TV series The Thick of It
- Jack Duggan (ice hockey), ice hockey player
- Jack Duggan (politician), member of the Queensland Legislative Assembly
- John Duggan (political scientist) of the Duggan–Schwartz theorem