Colgan is an Irish surname, an Anglicized form of Irish Ó Colgáin meaning "descendant of Colga", a personal name based on colg "thorn," "sword." Notable people with the surname include:
Arthur Colgan (born 1946), American Roman Catholic bishop Carol Colgan (born 1960), Canadian rower Charles J. Colgan (1926–2017), American Democratic politician and businessman from Virginia Eileen Colgan (c. 1934–2014), Irish actress Flavia Colgan, American Democratic strategist Gerry Colgan (1951–2011), Scottish teacher and footballer Gregory Colgan (born 1953), Australian cricketer Jenny Colgan, British novelist John Colgan, Irish hagiographer and historian Michael Colgan (disambiguation), multiple people Nick Colgan, Irish football goalkeeper Stevyn Colgan, Cornish writer, artist and songwriter Diana Colgan, economist
See also Colgan, North Dakota, unincorporated community, United States Colgan Air, an American regional airline