genealogies of the families
Quinn is one of the most numerous Irish surnames. The number of people in Ireland so called at the present day being estimated at seventeen thousand: in the list of commonest surnames it occupies twentieth place in the country as a whole and first place in Co. Tyrone, though widespread in many counties.
Tyrone is the place of origin of one of the five distinct septs of this name. The most notable were the Dalcassian sept of Thomond, whose territory lay around Corofin, in the barony of Inchiquin, Co. Clare, and that of Antrim, where the Quinns have long been associated with the Glens of Antrim.
The O'Quinns of Co. Longford were also an important sept, being of the same stock as the O'Ferralls of Annaly. It will be noticed that the place names Inchiquin, Ballyquin etc., are spelt with only one final N. There are two in Irish - O' Cuinn - which surname is formed from the personal name Conn. At the present time as a rule Catholic families use two Ns and Protestants one; but this practice is not invariable now, and was less so in the past.
The first of the Dalcassian sept to bear the surname was Niall O'Cuinn, who was killed at the battle of Clontarf in 1014. Among prominent men of the name James Quin (I693-1766), the famous actor, and Walter Quin (1575-1634), the Dublin born poet who was tutor and lifelong associate of Charles 1, and his son James Quin (1621-1659), noted singer, may be specifically mentioned. The Franciscan Thomas O'Quinn was Bishop of Clonmacnois from 1252 to 1279, and John Quinn, a Dominican, was Bishop of Limerick from 1522 to 1551. Thady Quin (1645-1726), of Adare, who was a descendant of the Thomond O'Quins, was the grandfather of the first Earl of Dunraven: this peerage is one of the few held by old Gaelic families, others being O'Brien, O'Callaghan, O'Daly, O'Grady, MacLysaght and O'Neill.
Families of O'Quinn settled in France and became leading citizens both in Bordeaux and Pau. There is a street called Rue O'Quinn in Bordeaux, indicating the importance of the family, which is still extant in that part of France.
Source: Irish Families by Edward MacLysaght MA, D Litt, MRIA - Irish Academic Press 1991