Quinn is an Anglicised form of the Irish Ó Coinn or Mac Cuinn.
[2] The surname is borne by several unrelated families in Ireland, especially in the northern province of Ulster and also the counties of Clare, Longford, and Mayo.
[4] The most notable family of the name are that of Thomond, a Dalcassian sept,[5] who derive their surname from Niall Ó Cuinn who was slain at the Battle of Clontarf in 1014.
[7] Another family is that seated in Annaly, who were related to the O'Farrell lords of Longford.
Another Quinn family was seated at An Chraobh, County Tyrone and they were related to the O'Neill Kings of Tír Eoghain and for whom they acted as Hereditary Quartermasters.