Common Irish Last Names: A Comprehensive Guide

Discover the rich history and diverse meanings behind some of the most common Irish last names. This comprehensive list delves into the origins and significance of these surnames, offering insights into the cultural tapestry of Ireland. From ancient Gaelic roots to anglicized versions, explore the stories woven into the fabric of Irish identity through these enduring names.
1. **Murphy:** meaning "sea warrior" or "descendant of Murchad" (a Gaelic personal name meaning "sea warrior"). This is one of the most common Irish surnames, originating in County Cork.
2. **Kelly:** meaning "bright," "handsome," or "warlike," derived from the Gaelic word "Caoimhe." It's widespread throughout Ireland, particularly in counties like Galway, Mayo, and Tipperary.
3. **O'Brien:** meaning "descendant of Brian," a powerful and influential Gaelic king. This surname is found primarily in counties like Clare, Limerick, and Tipperary.
4. **Ryan:** meaning "little king" or "descendant of Rían," a popular Gaelic personal name. This surname is common in counties like Tipperary, Kilkenny, and Laois.
5. **Walsh:** meaning "strong," "powerful," or "lord" - derived from the Gaelic word "Uallach." This surname is prevalent in counties like Dublin, Kildare, and Meath.
6. **O'Connor:** meaning "descendant of Connor," a significant Gaelic name associated with kings and warriors. This surname is found in counties like Roscommon, Sligo, and Mayo.
7. **O'Neill:** meaning "descendant of Niall," a legendary high king of Ireland. This surname is prevalent in counties like Ulster, Tyrone, and Armagh.
8. **O'Reilly:** meaning "descendant of Rígh Fhiola," meaning "king of Fíol," a territory in County Cavan. This surname is commonly found in counties like Cavan, Monaghan, and Louth.
9. **McCarthy:** meaning "son of Carthaigh," a Gaelic name meaning "lover" or "beloved." This surname is prominent in counties like Cork, Kerry, and Waterford.
10. **O'Sullivan:** meaning "descendant of Súilleabháin," a Gaelic name meaning "black-eyed" or "dark-haired." This surname is prevalent in counties like Cork, Kerry, and Waterford.
11. **O'Shaughnessy:** meaning "descendant of Seán Ó Séaghdha," a Gaelic name meaning "God is gracious." This surname is found in counties like Galway, Mayo, and Roscommon.
12. **O'Connell:** meaning "descendant of Conchobhair," a Gaelic name meaning "desirable" or "handsome." This surname is prevalent in counties like Kerry, Cork, and Limerick.
13. **O'Doherty:** meaning "descendant of Doirthe," a Gaelic name meaning "blackthorn." This surname is found in counties like Donegal, Derry, and Tyrone.
14. **O'Toole:** meaning "descendant of Tuathal," a Gaelic name meaning "strong" or "noble." This surname is prevalent in counties like Dublin, Wicklow, and Kildare.
15. **O'Carroll:** meaning "descendant of Cathal," a Gaelic name meaning "strong" or "mighty." This surname is found in counties like Offaly, Tipperary, and Limerick.
16. **O'Malley:** meaning "descendant of Máel," a Gaelic name meaning "chief" or "lord." This surname is prevalent in counties like Galway, Mayo, and Roscommon.
17. **O'Hanlon:** meaning "descendant of Anluan," a Gaelic name meaning "beautiful" or "handsome." This surname is found in counties like Armagh, Monaghan, and Louth.
18. **O'Flynn:** meaning "descendant of Flann," a Gaelic name meaning "red" or "ruddy." This surname is prevalent in counties like Cork, Kerry, and Limerick.
19. **O'Driscoll:** meaning "descendant of Diarmaid," a Gaelic name meaning "successful" or "victorious." This surname is prevalent in counties like Cork, Kerry, and Waterford.
20. **O'Donovan:** meaning "descendant of Domhnall," a Gaelic name meaning "world ruler" or "lord." This surname is prevalent in counties like Cork, Kerry, and Waterford.
21. **O'Mara:** meaning "descendant of Meara," a Gaelic name meaning "sea warrior" or "descendant of Murchad." This surname is found in counties like Kilkenny, Tipperary, and Waterford.
22. **O'Meara:** meaning "descendant of Maolmhíara," a Gaelic name meaning "bald" or "smooth." This surname is prevalent in counties like Offaly, Tipperary, and Limerick.
23. **O'Callaghan:** meaning "descendant of Colla," a Gaelic name meaning "victory" or "triumph." This surname is prevalent in counties like Cork, Kerry, and Limerick.
24. **O'Shea:** meaning "descendant of Ó Sé," a Gaelic name meaning "descendant of John." This surname is prevalent in counties like Kerry, Cork, and Limerick.
25. **O'Brien:** meaning "descendant of Brian," a powerful and influential Gaelic king. This surname is found primarily in counties like Clare, Limerick, and Tipperary.
26. **O'Reilly:** meaning "descendant of Rígh Fhiola," meaning "king of Fíol," a territory in County Cavan. This surname is commonly found in counties like Cavan, Monaghan, and Louth.
27. **O'Neill:** meaning "descendant of Niall," a legendary high king of Ireland. This surname is prevalent in counties like Ulster, Tyrone, and Armagh.
28. **O'Connor:** meaning "descendant of Connor," a significant Gaelic name associated with kings and warriors. This surname is found in counties like Roscommon, Sligo, and Mayo.
29. **O'Toole:** meaning "descendant of Tuathal," a Gaelic name meaning "strong" or "noble." This surname is prevalent in counties like Dublin, Wicklow, and Kildare.
30. **O'Doherty:** meaning "descendant of Doirthe," a Gaelic name meaning "blackthorn." This surname is found in counties like Donegal, Derry, and Tyrone.
31. **O'Callaghan:** meaning "descendant of Colla," a Gaelic name meaning "victory" or "triumph." This surname is prevalent in counties like Cork, Kerry, and Limerick.
32. **O'Flynn:** meaning "descendant of Flann," a Gaelic name meaning "red" or "ruddy." This surname is prevalent in counties like Cork, Kerry, and Limerick.
33. **O'Hanlon:** meaning "descendant of Anluan," a Gaelic name meaning "beautiful" or "handsome." This surname is found in counties like Armagh, Monaghan, and Louth.
34. **O'Driscoll:** meaning "descendant of Diarmaid," a Gaelic name meaning "successful" or "victorious." This surname is prevalent in counties like Cork, Kerry, and Waterford.
35. **O'Sullivan:** meaning "descendant of Súilleabháin," a Gaelic name meaning "black-eyed" or "dark-haired." This surname is prevalent in counties like Cork, Kerry, and Waterford.
36. **O'Mara:** meaning "descendant of Meara," a Gaelic name meaning "sea warrior" or "descendant of Murchad." This surname is found in counties like Kilkenny, Tipperary, and Waterford.
37. **O'Shaughnessy:** meaning "descendant of Seán Ó Séaghdha," a Gaelic name meaning "God is gracious." This surname is found in counties like Galway, Mayo, and Roscommon.
38. **O'Donovan:** meaning "descendant of Domhnall," a Gaelic name meaning "world ruler" or "lord." This surname is prevalent in counties like Cork, Kerry, and Waterford.
39. **O'Malley:** meaning "descendant of Máel," a Gaelic name meaning "chief" or "lord." This surname is prevalent in counties like Galway, Mayo, and Roscommon.
40. **O'Carroll:** meaning "descendant of Cathal," a Gaelic name meaning "strong" or "mighty." This surname is found in counties like Offaly, Tipperary, and Limerick.
41. **O'Meara:** meaning "descendant of Maolmhíara," a Gaelic name meaning "bald" or "smooth." This surname is prevalent in counties like Offaly, Tipperary, and Limerick.
42. **O'Shea:** meaning "descendant of Ó Sé," a Gaelic name meaning "descendant of John." This surname is prevalent in counties like Kerry, Cork, and Limerick.