Top 100+ Irish Surnames and Their Unique Meanings Explained

Ever wonder what your surname says about your heritage?

Irish surnames are far more than just family labels. They are cultural fingerprints, carrying echoes of ancient Gaelic clans, medieval kings, Celtic warriors, and the landscapes of Ireland itself. From prefixes like O’ and Mac, to rare names tied to forgotten chieftains, Irish last names reveal stories about ancestry, identity, and migration. Whether you're researching your Irish roots, building a family tree, or simply curious about traditional Gaelic naming customs, this guide will take you into the fascinating world of Irish surnames and their unique meanings.

Before diving into the full list of the 101 most common and rare Irish surnames, it’s important to understand one thing: Irish surnames didn’t appear randomly. They evolved through centuries of clan systems, Norman influence, anglicization, and deep Celtic tradition. Each surname is almost like a historical record—encoded in language.

Now, let’s explore how these names began.

Irish surnames(órfhocal), also known as Gaelic family names, are among the oldest hereditary surnames in Europe. The emergence of surnames in Ireland dates back to the 11th century, when communities needed a way to distinguish individuals beyond a single given name. Most traditional Irish last names come from four major sources:

Many Irish names originate from an ancestor or father’s name, often using:

• O’ (Ó) = “descendant of”

• Mac = “son of”

Examples include O’Brien (descendant of Brian) or MacCarthy (son of Cárthach).

Some surnames describe the land or region a family belonged to, linked to counties like Cork, Kerry, or Donegal. This is common in Irish surnames by county and regional clan heritage.

Certain names came from professions, roles, or societal positions, such as storytellers, clerics, or warriors.

Example: Ward, meaning “son of the bard.”

Some surnames in Irish originated from physical traits, personality, or legendary deeds, making them some of the most colorful and rare Irish family names today. Over centuries of invasion, Norman settlement, and English rule, many surnames were anglicized—yet their Gaelic identity remains strong.

Not all Irish surnames are common. Some are considered rare Irish surnames, tied to specific clans or ancient chieftain families. Here are some fascinating, uncommon names:

1. MacDermott (Mac Diarmada): Pronunciation "Mak-DER-mit", meaning "son of Diarmaid," associated with a historic Connacht chieftain.

2. O’Keefe (Ó Caoimh): Pronounced "Oh-KEEF", meaning “descendant of Caoimh” (gentle, noble). This surname is still strongly linked to County Cork.

3. Fagan (Ó Faodhagáin): Pronounced "FAY-gan", meaning “fiery one” or “ardent spirit”. A rare Irish surname with Norman-Irish overlap.

4. Sweeney (Mac Suibhne): Pronunciation "SWEE-nee", meaning: “pleasant one”. An ancient Donegal clan name.

5. Tierney (Ó Tiarnaigh): Pronounced "TEER-nee", meaning “master” or “lord-like”. One of the more elegant traditional Irish family names.

The following are among the most common Irish surnames worldwide, especially across Ireland, the US, Canada, and Australia due to Irish diaspora migration.

6. O’Driscoll (Ó hEidirsceoil): Pronounced "Oh-DRIS-kul", meaning “bearer of news”. A famous Munster surname.

7. Donovan (Ó Donnabháin): Pronounced "DUN-uh-van", meaning “descendant of the dark brown-haired chieftain,” a powerful surname in southern Ireland.

8. Kearney (Ó Catharnaigh): Pronounced "KAR-nee", meaning “victorious,” a surname historically associated with warriors and leaders.

9. O’Brien (Ó Briain): Pronounced "Oh-BRY-en", meaning “descendant of Brian”. Linked directly to High King Brian Boru.

10. Ryan (Ó Riain): Pronounced "RYE-an", Ryan is one of the most well-known Irish surnames, meaning “little king,” making it especially popular among families exploring royal Gaelic roots.

11. O’Sullivan (Ó Súilleabháin): Pronounced "Oh-SUL-ih-van", meaning “dark-eyed” or “hawk-eyed,” one of the most powerful Kerry clan surnames.

12. O’Connor (Ó Conchobhair): Pronounced "Oh-KON-er", meaning “descendant of Conchobhar”. One of the most ancient royal Irish surnames.

13. Walsh (Breathnach): Pronounced "WAWL-sh", meaning “Welshman” or “foreigner”. A Norman-era surname widely spread today.

14. McCarthy (Mac Cárthaigh): Pronounced "Mak-KAR-thee", meaning “son of Cárthach,” a major surname of Munster Gaelic nobility.

15. Doyle (Ó Dubhghaill): Pronounced "DOYL", meaning “dark stranger”. Some Irish surnames, like Doyle, may even reflect Ireland’s Viking past, preserving traces of Norse settlements along the coast.

16. Murphy (Ó Murchadha): Pronounced "MUR-fee", meaning “sea warrior” or “sea battler,” one of the most common Irish surnames in America today.

17. Campbell (from Gaelic Caimbeul): Pronounced "KAM-bul", meaning “crooked mouth,” originally a nickname that became one of the most recognizable Irish and Scottish surnames.

18. Murray(Ó Muireadhaigh): Pronounced "MUR-ee", meaning “settlement by the sea,” a surname strongly associated with coastal Irish clans.

19. Nolan (Ó Nualláin): Pronounced "NOH-lan", from an ancient Gaelic name meaning “famous” or “noble,” often linked to respected family lines in medieval Ireland.

20. Bell (Belle): Pronounced "BEL", derived from the Old English word Belle, meaning “bell ringer” or “bell maker,” showing the blend of Norman and Irish surname history.

21. Kenny (Ó Cionaoith): Pronounced "KEN-ee", meaning “fiery love” or “fire-born,” a traditional Irish surname connected to passion and strength in Gaelic naming.

22. Fitzpatrick (Mac Giolla Phádraig): Pronounced "FITZ-PAT-rik", meaning “devotee of Saint Patrick,” one of the most historically significant Irish surnames tied to religious heritage.

23. Gallagher (Ó Gallchobhair): Pronounced "GAL-uh-her", often interpreted as “helper” or “stranger,” a famous Donegal surname with strong Gaelic roots.

24. Hayes (Ó hAodha): Pronounced "HAYZ", meaning “fire,” derived from the name Aodh, a common figure in Irish mythology and ancient kingship.

25. Flynn (Ó Floinn): Pronounced "FLIN", meaning “descendant of the red-haired one,” a classic Irish surname inspired by physical traits.

26. Barry (Ó Beargha or Ó Báire): Pronounced "BAIR-ee", meaning “spear-like” or “plunderer,” a surname reflecting both warrior imagery and Norman influence in Ireland.

27. Regan (Ó Riagáin): Pronounced "RAY-gan", meaning “the king’s child,” a surname often connected to early Gaelic nobility.

28. Whelan (Ó Faoláin): Pronounced "HWEH-lan or WAY-lan", meaning “wolf,” one of several Irish surnames rooted in animal symbolism and clan identity.

29. O’Neill (Ó Néill): Pronounced "Oh-NEEL", meaning “descendant of Niall,” one of the most powerful royal surnames in Irish history, linked to the legendary High Kings.

30. Egan (Mac Aodhagáin): Pronounced "EE-gan", meaning “little bright-eyed one,” originally associated with learned families and historians in Gaelic Ireland.

31. Muldoon (Ó Maoldúin): Pronounced "Mul-DOON", meaning “descendant of the disciple of Saint Dúin,” reflecting Ireland’s deep monastic and spiritual surname origins.

32. O’Carroll (Ó Cearbhaill): Pronounced "Oh-KAIR-uhl", meaning “disputed” or “fierce in battle,” a surname belonging to several prominent Irish ruling families.

33. Nolan (Ó Nualláin): Pronounced "NOH-lan", meaning “noble” or “famous,” a reminder that many Irish surnames have multiple historical branches.

34. Phelan (Ó Faoláin): Pronounced "FEE-lan", meaning “wolf,” closely related to Whelan and common among families in southeastern Ireland.

35. Cosgrave (Ó Coscraigh): Pronounced "KOZ-grayv", meaning “son of Coscrach,” traditionally linked to warriors and defenders in Gaelic society.

36. Byrne (Ó Broin): Pronounced "BURN", meaning “descendant of Bran” or “raven,” one of Ireland’s best-known surnames tied to Leinster clans.

37. Flannery (Ó Flannghaile): Pronounced "FLAN-uh-ree", meaning “red valor,” an Irish surname associated with courage and heroic reputation.

38. McMahon (Mac Mathghamhna): Pronounced "Mak-MAH-hun", meaning “son of the bear,” a powerful surname common in Ulster with strong clan heritage.

39. Tracy (Ó Treasaigh): Pronounced "TRAY-see", meaning “fighter” or “warrior,” reflecting the martial tradition in many old Irish family names.

40. Coughlan (Mac Cochláin): Pronounced "KOK-lan", meaning “son of the one with the cloak,” likely originating from a descriptive Gaelic nickname.

41. McGee (Mac Aodha): Pronounced "Mak-GEE", meaning “son of Aodh,” with Aodh meaning “fire,” a name shared by many ancient Irish kings.

42. Hennessy (Ó hAonghusa): Pronounced "HEN-uh-see", meaning “descendant of Angus,” a surname with strong Munster roots and Gaelic nobility associations.

43. Keating (Céitinn): Pronounced "KEE-ting", a surname of Norman origin that became deeply established in Irish genealogy over centuries.

44. Molloy (Ó Maolmhuaidh): Pronounced "Muh-LOY", meaning “proud chieftain,” a traditional Irish surname connected to leadership and clan prestige.

45. Heany (Ó hEignigh): Pronounced "HEE-nee", meaning “horseman,” a surname linked to riders and Gaelic warrior heritage.

46. Dempsey (Ó Díomasaigh): Pronounced "DEMP-see", meaning “proud,” reflecting dignity and strong Irish clan identity.

47. McManus (Mac Mághnais): Pronounced "Mak-MAN-us", meaning “son of Magnus,” showing traces of Norse influence in Irish surnames.

48. Boyle (Ó Baoighill): Pronounced "BOYL", meaning “descendant of Baoigheall,” a well-known surname rooted in Donegal ancestry.

49. O’Houlihan (Ó hUallacháin): Pronounced "Oh-HOO-li-han", meaning “proud” or “noble,” often associated with traditional Munster families.

50. McGovern (Mág Samhradháin): Pronounced "Mak-GUV-ern", meaning “son of Samhradhán,” historically connected to Gaelic chiefs in County Cavan.

51. Keenan (Ó Cianáin): Pronounced "KEE-nan", meaning “descendant of the faithful one,” a surname tied to loyalty and devotion in Irish culture.

52. Colgan (Ó Colgáin): Pronounced "KOL-gan", meaning “sword,” a powerful Irish surname reflecting warrior symbolism.

53. Duffy (Ó Dubhthaigh): Pronounced "DUFF-ee", meaning “descendant of Dubthach,” often linked to the Gaelic word for “dark” or “black.”

54. Kelly (Ó Ceallaigh): Pronounced "KEL-ee", meaning “warrior” or “fighter,” one of the most widespread Irish surnames worldwide.

55. Crean (Ó Croidheagáin): Pronounced "KREEN", meaning “descendant of Croidheagan,” a rare Irish surname with deep Gaelic lineage.

56. Mulligan (Ó Maolagáin): Pronounced "MUL-i-gan", meaning “grandson of the bald man,” originally a descriptive medieval Irish family name.

57. Geoghegan (Mag Eochagáin): Pronounced "GYO-gan", meaning “horse,” strongly associated with ancient Irish nobility in the Midlands.

58. Scully (Ó Scolaidhe): Pronounced "SKUL-ee", meaning “descendant of Scolaidhe,” a surname linked to scholarly Gaelic families.

59. Madden (Madadhan): Pronounced "MAD-en", meaning “little dog,” a charming example of Irish surnames derived from nicknames.

60. Hegarty (Ó hÉigeartuigh): Pronounced "Heh-GAR-tee", a traditional Irish surname most commonly found in Ulster regions.

61. Tiernan (Ó Tiarnáin / MacTiarnaigh): Pronounced "TEER-nan", meaning “master” or “lord,” reflecting authority in Gaelic society.

62. McKeogh (Mac Eochaidh): Pronounced "Mak-KYOH", meaning “son of Eochaidh,” with roots in ancient royal Irish naming traditions.

63. Gorman (Mac Gormáin): Pronounced "GOR-man", meaning “dark blue” or “noble,” a surname historically associated with high-status Gaelic clans.

These surnames are deeply connected to Ireland’s medieval clan structure and are often considered authentic Gaelic Irish last names.

64. O’Cleary (Ó Cléirigh): Pronounced "Oh-KLAIR-ee", meaning “clerk” or “cleric,” a surname historically linked to learned and religious families in Gaelic Ireland.

65. McCloskey (Mac bhLoscaidh): Pronounced "Mak-KLOSS-kee", meaning “son of Bloscadh,” a traditional Irish surname strongly associated with Ulster roots.

66. Brennan (Ó Branáin / Ó Braonáin): Pronounced "BREN-an", meaning “descendant of Branán,” with Bran often connected to the raven in Celtic symbolism.

67. Cahill (Cathail): Pronounced "KAH-hill", meaning “strong in battle,” a surname reflecting warrior strength in early Irish clan society.

68. Boland (Ó Beólláin): Pronounced "BOH-land", meaning “descendant of Beóllán,” an old Irish family name with deep Gaelic origins.

69. Canavan (Ó Ceanndubháin): Pronounced "KAN-uh-van", meaning “descendant of the dark-haired one,” originally describing physical traits in medieval Ireland.

70. Dwyer (Ó Duibhir): Pronounced "DWY-er", meaning “dark-colored,” a surname often associated with traditional Munster Irish families.

71. Cullen (Ó Cuileáin): Pronounced "KUL-en", meaning “young hound” or “handsome one,” a classic example of Irish surnames derived from nicknames.

72. Finnegan (Ó Fionnagáin): Pronounced "FIN-uh-gan", meaning “son of the fair-haired one,” a well-known surname rooted in ancient Gaelic lineage.

73. Gaffney (Ó Gamhna): Pronounced "GAF-nee", meaning “calf,” a rare Irish surname possibly connected to pastoral life and symbolism.

74. Kennedy (Ó Ceannéidigh): Pronounced "KEN-uh-dee", meaning “grandson of Ceannéidigh,” a surname long associated with noble Gaelic leadership.

75. Ward (Mac an Bhaird): Pronounced "WARD", meaning “son of the bard,” famously tied to storytelling and poetic families in Gaelic Ireland.

76. Flanagan (Ó Flannagáin): Pronounced "FLAN-uh-gan", meaning “red” or “ruddy,” often linked to physical traits in early Irish communities.

77. Brady (Ó Brádaigh): Pronounced "BRAY-dee", meaning “broad” or “spirited,” a surname reflecting bold personality in Irish tradition.

78. Collins (Ó Coileáin): Pronounced "KOL-inz", meaning “darling,” a surname connected to warmth and affection in Gaelic naming culture.

79. Donohoe (Ó Donnchadha): Pronounced "DON-uh-hoh", meaning “brown-haired warrior,” combining both appearance and battle heritage.

80. Donnelly (Ó Donnghaile): Pronounced "DON-uh-lee", meaning “brown valor,” a surname tied to courage and Gaelic warrior identity.

81. Quinn (Ó Coinn / Mac Cuinn): Pronounced "KWIN", meaning “son of Conn,” with Conn being a legendary name among ancient Irish kings.

82. Dunne (Ó Duinn): Pronounced "DUN", meaning “brown” or “dark,” one of the classic Irish surnames derived from descriptive traits.

83. Boylan (Ó Baoighealláin): Pronounced "BOY-lan", meaning “descendant of Baoigheallán,” a traditional Irish surname with strong Gaelic family roots.

Due to the Great Famine and mass emigration, many Irish surnames became iconic in the United States.

84. Moloney (Ó Maoldomhnaigh): Pronounced "Muh-LONE-ee", meaning “descendant of the servant of the church,” a surname closely tied to early Irish religious communities.

85. Maher (Ó Meachair): Pronounced "MAH-her", meaning “descendant of a kind chief,” often associated with respected Gaelic leadership.

86. Moran (Ó Móráin): Pronounced "MOHR-an", meaning “big chieftain,” a surname reflecting power and high status in Irish clan society.

87. Mullen (Ó Maoláin): Pronounced "MUL-en", meaning “descendant of Maolán,” a traditional Irish family name with deep Gaelic roots.

88. Healy (Ó hEalaighthe): Pronounced "HEE-lee", meaning “ingenious,” a surname linked to creativity and intelligence in Irish tradition.

89. Higgins (Ó hUiginn): Pronounced "HIG-inz", meaning “sea rover,” possibly connected to maritime life and ancient seafaring heritage.

90. Hogan (Ó hÓgáin): Pronounced "HOH-gan", meaning “young warrior,” one of the well-known Irish surnames associated with bravery.

91. Hughes (Ó hAodha): Pronounced "HYOOZ", meaning “descendant of Aodh,” with Aodh meaning “fire,” a name common among ancient Irish kings.

92. Magee (Mag Aodha): Pronounced "Muh-GEE", meaning “son of Aodh,” another surname rooted in the powerful Gaelic fire-name tradition.

93. Maguire (Mac Uidhir): Pronounced "Muh-GWY-er", meaning “son of Odhar” or “dark one,” a famous Irish surname strongly linked to Fermanagh nobility.

94. Moore (Ó Mórdha): Pronounced "MOHR", meaning “noble and stately,” one of the most widespread Irish surnames across the diaspora.

95. Martin (Mac Giolla Mhártain): Pronounced "MAR-tin", meaning “son of the follower of Saint Martin,” reflecting Ireland’s Christian surname influences.

96. Kane (Ó Catháin): Pronounced "KAYN", a classic Irish surname connected to ancient warrior families in Ulster.

97. Kavanagh (Caomhánach): Pronounced "KAV-uh-nah", meaning “follower of Saint Caomhan,” a surname with strong monastic and historical roots.

98. Keane (Ó Catháin): Pronounced "KEEN", meaning “courageous warrior,” often associated with bravery in Gaelic clan heritage.

99. Sheehan (Ó Síodhacháin): Pronounced "SHEE-an", meaning “the peaceful one,” a surname reflecting calmness and harmony in Irish naming.

100. Foley (Foghlú): Pronounced "FOH-lee", meaning “plunderer,” a surname with echoes of medieval conflict and warrior culture.

101. Connolly (Ó Conghalaigh): Pronounced "KON-uh-lee", meaning “fierce as a hound,” a powerful traditional Irish surname tied to strength and loyalty.

Irish surnames are more than simple last names. They are living echoes of Ireland’s clans, saints, warriors, poets, and landscapes. Each of these Irish surnames and meanings offers a personal gateway into the past—helping you connect with ancestry, geography, and Celtic identity. So whether your surname is O’Brien, Murphy, Tierney, or a rare name known only in one Irish county, you carry a piece of Ireland’s story with you.

Ireland's surnames are more than just family names; they are gateways into Ireland’s rich cultural history and identity. Each surname reflects ancestry, geography, and centuries of Gaelic tradition. To deepen this connection, many people also explore Irish boy names and meanings and Irish girl names, which share the same ancient roots found in Irish surnames. Together, these traditional names preserve Ireland’s legacy and help keep its heritage alive for generations to come.