Colgan is an Irish surname, an Anglicized form of Irish Ó Colgáin meaning "descendant of Colga", a personal name based on colg "thorn," "sword."
Colgan is an Irish surname that derives from the Irish Ó Colgáin. This family name signifies descent from a person named Colga, whose name is based on the term colg which means "thorn" or "sword."