Irish Surname Origins & Genealogy Resources
Origin of Irish Surnames
Irish Family Names
Irish surnames have Gaelic and Norman roots. In Northern Ireland, English and Scottish names, derived from the Gaelic, can also be found. During the 1600s and 1700s, when Irish names were discouraged, some Irish families adopted English surnames.
Many Irish names have an "O" or "Mc" prefix. "O" means grandson and "Mc" means son. During the 1700s and early 1800s, when the Irish language was dying, there was a gradual dropping of the "O" and "Mc" from names. As awareness of Gaelic heritage was renewed, these prefixes were restored. When searching for Irish names, be sure to check your surname both with and without the prefix e.g. Sullivan and O'Sullivan.
- Patronymic Surnames
Suffix mean "son of"
Mac, Mc - son of
O' - grandson of
- Geographical Surnames
Suffix Derived from nearby locations. Bally– (town), –more (big), or –beg (small)
Some of the most common Irish surnames in the US: