The most common Irish family name of all is Murphy, which means "sea battler." The name originated with the Gaelic MacMurchadh and O'Murchadh, meaning son and descendant of Murchadh, respectively, and became MacMurphy and then Murphy in the 19th century. The second most common name in Ireland is Kelly, which means "the bright-headed ones" and originated with the Gaelic O Ceallach, "descended from Ceallach," the Irish chieftain.Continue Reading
O'Sullivan, which in Irish Gaelic is spelled O'Suilleabhin, contains the word "sul," meaning "eye." The name translates to either "one-eyed" or "hawk-eyed."
When a last name begins with the letter O and an apostrophe, this typically indicates ancestry. Many of these names have been anglicized from the Gaelic Irish original. O'Reilly, for example, was originally O'Raghailligh, meaning "descendant of Reghaillach." O'Neill is derived from a more specific genealogical reference: "Ua Niall," meaning "grandson of Niall." According to legendary history, Niall of the Nine Hostages brought St. Patrick, Ireland's patron saint, to the country in the 4th century.
The common Irish family name Ryan derives from the Gaelic word "righ" and the Irish "an," which translates together as "little kings." Like many other Irish names, it originally indicated ancestry as "O'Riain" and the earlier "O'Mulriain."Learn more about Genealogy