Irish Last Names: Origins, Meanings, and Significance

Origins of Irish Last Names

Irish last names have a rich history that is deeply intertwined with the country’s culture and traditions. Many of these surnames have their roots in the Gaelic and Celtic languages, which were spoken in Ireland for centuries. The Norman invasion of Ireland in the 12th century also had a significant impact on Irish last names.

Before the Norman invasion, the use of surnames in Ireland was not widespread. People were usually identified by their first name and their father’s name. For example, Brian mac Donnchadh (Brian, son of Donnchadh). However, as the country became more settled, the use of surnames became more common.

Many Irish last names begin with “O” or “Mac,” which means “descendant of” in Gaelic. For example, O’Brien means “descendant of Brian,” and MacCarthy means “descendant of Carthach.” These prefixes were used to distinguish between people with the same first name.

Irish last names can also be based on a person’s occupation or physical characteristics. For example, the name Smith comes from the Old English word “smitan,” which means to strike or hit. This name was given to blacksmiths, who were skilled metalworkers. Other occupational names include Cooper, Taylor, and Carpenter.

In addition to occupation-based names, Irish last names can also be based on a person’s physical characteristics. For example, the name Flanagan comes from the Gaelic word “flann,” which means red or ruddy. This name was given to people with red hair or a ruddy complexion. Other physical characteristic-based names include Reid (red-haired) and Duffy (dark-haired).

Whether based on Gaelic, Celtic, or Norman roots, these names are an important part of Ireland’s heritage.

Irish Last Names - Irish people scene

Common Prefixes in Irish Surnames

Irish surnames often have prefixes that indicate a patronymic or ancestral lineage. Mc and Mac are more common in the northern part of Ireland, while O is more common in the southern part. Fitz is more common among the Anglo-Irish families.

Prefix ‘Mc’ and ‘Mac’

Irish surnames often start with prefixes such as Mc and Mac. These prefixes mean “son of” and are used to indicate a patronymic lineage. Mc is the anglicized version of the Gaelic prefix “Mac,” which is still used in modern Irish. The use of Mc and Mac was more common in the northern part of Ireland.

For example, the surname “McCarthy” means “son of Carthy,” while “MacDonald” means “son of Donald.” The use of Mc or Mac was followed by the father’s first name. So, if the father’s name was John, the son’s name would be John Mc or Mac. Manannan Mac Lir is an example of a mythical figure with this name. 

Prefix ‘O’

Another common prefix in Irish surnames is “O,” which means “grandson of” or “descendant of.” This prefix is followed by the name of the ancestor. The use of O was more common in the southern part of Ireland.

For example, the surname “O’Brien” means “descendant of Brian,” while “O’Connor” means “descendant of Connor.”

It is important to note that the prefix O is not always used in modern Irish surnames. Some surnames dropped the O over time, while others added it to make their names sound more Irish. It is a common belief that a name which should have an O (eg. O’ Sullivan) which no longer has an O (eg. Sullivan) is due to that person’s family ‘taking the soup’. Taking the soup refers to the family converting to Protestantism during the Irish Famine in order to receive food to ensure their survival.

Prefix ‘Fitz’

The prefix “Fitz” is another common prefix in Irish surnames. It comes from the Norman-French word “fils,” meaning “son of.” The Normans introduced this prefix to Ireland in the 12th century.

For example, the surname “Fitzgerald” means “son of Gerald,” while “Fitzpatrick” means “son of Patrick.”

The use of Fitz was more common among the Anglo-Irish families in Ireland.

Popular Irish Last Names

Irish last names have a rich history and cultural significance. Many of these surnames have been passed down through generations and are still commonly used today. Here are some of the most popular Irish surname meanings.

Kelly

The name Kelly is derived from the Irish “Ó Ceallaigh” which means “descendant of Ceallach”. Ceallach was an Irish king who ruled during the 10th century. The name Kelly is most commonly found in the western counties of Ireland.

Kennedy

The name Kennedy is derived from the Irish “Ó Cinnéide” which means “descendant of Cinnédidh”. The name Cinnédidh means “helmet-headed” or “armored-headed”. The Kennedys were a powerful clan in medieval Ireland and were known for their military prowess. Of course, the most famous Kennedy in recent times is President Kennedy who was of Irish origin

Doyle

The name Doyle is derived from the Irish “Ó Dubhghaill” which means “descendant of Dubhghall”. Dubhghall means “dark stranger” or “dark foreigner”. The name Doyle is most commonly found in the southeastern counties of Ireland.

King

The name King is derived from the Irish “Ó Cuinn” which means “descendant of Conn”. Conn was a legendary king of Ireland and Ireland’s first High King who ruled during the 2nd century. The name King is most commonly found in the northern counties of Ireland.

Fitzgerald

The name Fitzgerald is derived from the Norman French “FitzGerald” which means “son of Gerald”. The Fitzgeralds were a powerful Norman family who settled in Ireland during the 12th century. The name Fitzgerald is most commonly found in the southern counties of Ireland.

McCarthy

The name McCarthy is derived from the Irish “Mac Cárthaigh” which means “son of Cárthach”. The name Cárthach means “loving”. The McCarthy clan was one of the most powerful clans in medieval Ireland and were known for their military prowess.

Byrne

The name Byrne is derived from the Irish “Ó Broin” which means “descendant of Bran”. Bran means “raven”. The name Byrne is most commonly found in the eastern counties of Ireland.

Ryan

The name Ryan is derived from the Irish “Ó Riain” which means “descendant of Rian”. Rian means “little king”. The name Ryan is most commonly found in the western counties of Ireland.

Walsh

The name Walsh is derived from the Welsh “Breathnach” which means “Welshman”. The name Walsh is most commonly found in the southern counties of Ireland.

Murphy

The name Murphy is derived from the Irish “Ó Murchadha” which means “descendant of Murchadh”. Murchadh means “sea warrior”. The name Murphy is one of the most common surnames in Ireland and is most commonly found in the western counties of Ireland.

O’Connor

The name O’Connor is derived from the Irish “Ó Conchobhair” which means “descendant of Conchobhar“. Conchobhar means “lover of hounds”. The O’Connors were a powerful clan in medieval Ireland and were known for their military prowess.

Gallagher

The name Gallagher is derived from the Irish “Ó Gallchobhair” which means “descendant of Gallchobhar”. Gallchobhar means “foreign help”. The name Gallagher is most commonly found in the northern counties of Ireland.

Sullivan

The name Sullivan is derived from the Irish “Ó Súilleabháin” which means “descendant of Súilleabhán”. Súilleabhán means “little dark eye”. The name Sullivan is most commonly found in the southern counties of Ireland.

Doherty

The name Doherty is derived from the Irish “Ó Dochartaigh” which means “descendant of Dochartach”. Dochartach means “obstructive”. The name Doherty is most commonly found in the northern counties of Ireland.

Burke

The name Burke is derived from the Norman French “de Burgh” which means “from the town”. The Burkes were a powerful Norman family who settled in Ireland during the 12th century. The name Burke is most commonly found in the western counties of Ireland.

Campbell

The name Campbell is derived from the Scottish “Cam Beul” which means “crooked mouth”. The Campbells were a powerful Scottish family who settled in Ireland during the 17th century. The name Campbell is most commonly found in the northern counties of Ireland.

Collins

The name Collins is derived from the Irish “Ó Coileáin” which means “descendant of Coileán”. Coileán means “whelp” or “young dog”. The name Collins is most commonly found in the southern counties of Ireland. Collins is the namesake of one of Ireland’s famous revolutionary

 

Irish Last Names by Region

Ulster

Ulster is one of the four provinces of Ireland and is located in the north of the island. The region is known for its rugged landscapes and rich history. Some of the most common Irish last names in Ulster include:

  • O’Neill: This name is associated with the ancient kings of Ulste and has roots in Gaelic mythology.
  • Gallagher: This name is derived from the Gaelic word for “foreign helper” and is common in counties Donegal and Tyrone.
  • McLaughlin: This name means “son of Lochlainn” and is associated with the ancient High Kings of Ireland.

Connacht

Connacht is another province of Ireland and is located in the west of the island. The region is known for its stunning coastline and rugged landscapes. Some of the most common Irish last names in Connacht include:

  • O’Connor: This name means “descendant of Conchobhar” and is associated with the ancient kings of Connacht.
  • Walsh: This name is derived from the Gaelic word for “Welshman” and is common in counties Galway and Mayo.
  • McDonagh: This name means “son of Donnchadh” and is associated with the ancient High Kings of Ireland.

Munster

Munster is a province of Ireland that is located in the south of the island. The region is known for its vibrant cities and stunning natural beauty. Some of the most common Irish last names in Munster include:

  • O’Brien: This name means “descendant of Brian” and is associated with the ancient High Kings of Ireland.
  • Ryan: This name means “little king” and is common in counties Tipperary and Limerick.
  • McCarthy: This name means “son of Carthach” and is associated with the ancient kings of Munster.

Leinster

Leinster is the fourth province of Ireland and is located in the east of the island. The region is known for its rich history and stunning landscapes. Some of the most common Irish last names in Leinster include:

  • Byrne: This name means “descendant of Bran” and is common in counties Wicklow and Dublin.
  • Doyle: This name means “descendant of Dubhghall” and is associated with the ancient kings of Leinster.
  • Kelly: This name means “bright-headed” and is common in counties Kildare and Kilkenny.
Irish Last Names - Irish people scene
Irish Last Names – Irish people scene

Irish Surnames by County

Irish surnames are deeply rooted in the country’s history and culture, reflecting the influence of the various waves of migration and invasion that have shaped Ireland over the centuries. Each Irish county has its own unique set of surnames that are more commonly found in that area than anywhere else in the country. Here are some of the most common Irish surnames by county:

Antrim

  • Smith
  • Brown
  • Campbell
  • Wilson
  • Graham

Armagh

  • Campbell
  • Hughes
  • Quinn
  • Murphy
  • McParland

Carlow

  • Murphy
  • Nolan
  • Byrne
  • Doyle
  • Kavanagh

Cavan

  • Smith
  • Reilly
  • Clarke
  • O’Reilly
  • Brady

Clare

  • McMahon
  • McNamara
  • O’Brien
  • Moloney
  • Lynch

Cork

  • Murphy
  • O’Sullivan
  • McCarthy
  • O’Callaghan
  • Walsh

Derry

  • Doherty
  • Gallagher
  • McLaughlin
  • O’Neill
  • Bradley

Donegal

  • Gallagher
  • Doherty
  • McLaughlin
  • Boyle
  • O’Donnell

Down

  • Campbell
  • Brown
  • Wilson
  • Hughes
  • Johnston

Dublin

  • Murphy
  • Byrne
  • Kelly
  • O’Brien
  • Walsh

Fermanagh

  • Maguire
  • Gallagher
  • McManus
  • Leonard
  • Johnston

Galway

  • Walsh
  • Burke
  • Kelly
  • Joyce
  • Connelly

Kerry

  • O’Sullivan
  • Murphy
  • O’Connor
  • Moriarty
  • Fitzgerald

Kildare

  • Byrne
  • Doyle
  • Murphy
  • Kelly
  • Dunne

Kilkenny

  • Murphy
  • Walsh
  • Byrne
  • Power
  • Ryan

Laois

  • Dunne
  • Kelly
  • Lalor
  • Delaney
  • Brennan

Leitrim

  • Gallagher
  • Reynolds
  • McWeeney
  • McTague
  • McGovern

Limerick

  • Ryan
  • O’Brien
  • Fitzgerald
  • Sheehan
  • Hayes

Longford

  • Reilly
  • Smith
  • O’Brien
  • Duffy
  • Brady

Louth

  • Byrne
  • Murphy
  • Callaghan
  • Carroll
  • Lennon

Mayo

  • Gallagher
  • O’Malley
  • Moran
  • Walsh
  • McDonagh

Meath

  • Byrne
  • Smith
  • Reilly
  • Farrell
  • Clarke

Monaghan

  • McMahon
  • Duffy
  • Connolly
  • McCabe
  • McPhillips

Offaly

  • Dunne
  • Kelly
  • Byrne
  • Egan
  • Molloy

Roscommon

  • Kelly
  • Higgins
  • Flynn
  • Beirne
  • O’Connor

Sligo

  • Gallagher
  • Brennan
  • McGowan
  • O’Hara
  • Gallagher

Tipperary

  • Ryan
  • Maher
  • O’Brien
  • Kennedy
  • Ryan

Tyrone

  • Quinn
  • McLaughlin
  • Gallagher
  • O’Neill
  • Campbell

Waterford

  • Power
  • Walsh
  • Murphy
  • Flynn
  • O’Brien

Westmeath

  • Byrne
  • Smith
  • Murphy
  • Martin
  • Daly

Wexford

  • Murphy
  • Walsh
  • Doyle
  • Byrne
  • Kehoe

Wicklow

  • Byrne
  • Doyle
  • Murphy
  • Kavanagh
  • Kelly

Irish surnames are a fascinating aspect of the country’s cultural heritage, and the distinct surnames by county reflect the unique history and traditions of each area. While many of these surnames are common across the country, it is interesting to see the variations that exist from one county to the next.

Meaning Behind Irish Last Names

Irish last names often have a rich history and meaning behind them. Many are derived from Gaelic or Old Irish, while others have been anglicized over time. Here are some common themes and meanings behind Irish last names:

Prefixes

As shown earlier, the prefix “Ó” or “O'” in Irish surnames means “descendant of” and is often followed by the name of an ancestor. For example, “Ó Briain” means “descendant of Brian.” Other prefixes include “Mac” or “Mc,” which also mean “son of.” Brian Boru (O Brian) is the most famous holder of this name in Ireland. 

Occupations

Many Irish surnames are derived from occupations, such as “Smith” or “Carpenter.” Some examples of Irish occupational surnames include “Farrell” (meaning “hero”), “Gallagher” (meaning “foreign helper”), and “Joyce” (meaning “lord”).

Geography

Irish last names can also be derived from a person’s geographic location, such as “Doherty” (meaning “descendant of the hurtful one”) or “McGuire” (meaning “son of the noble one”). Other examples include “Boyle” (meaning “small stream”) and “Kelly” (meaning “bright-headed”).

Nicknames

Nicknames were also commonly used as a basis for Irish surnames. For example, “Brogan” means “shoe,” while “Bannon” means “white.” Other examples include “Finnegan” (meaning “fair-haired”) and “O’Meara” (meaning “merry”).

Clan Names

Some Irish surnames are derived from clan names, such as “O’Connor” (meaning “descendant of Connor”) or “O’Neill” (meaning “descendant of Niall”). These surnames were often used by powerful families who ruled over a particular region.

Top 200 Irish Surnames

Irish surnames are a rich source of history and tradition. They often reveal something about the family’s origin, occupation, or personality traits. Here are the top 200 Irish surnames, along with their Irish surname meanings and origins:

Irish Last Names A – F

Surname Meaning
Ahern Lord of horses
Ahearn Lord of horses
Allen Little rock
Barry Spear
Beirne Spear
Brady Spirited, Broad
Brennan Sorrow
Brogan Small shoe
Byrne Raven
Cahill Battle rule
Callaghan Bright-headed
Carey Love
Carr Spear
Carroll Champion
Casey Vigilant in war
Clancy Red warrior
Clarke Clerk
Collins Young creature
Connelly Love of hounds
Connolly Fierce as a hound
Cooney Handsome
Corcoran Ruddy
Costello Son of the foreigner
Crowley Hard chief
Cullen Handsome
Curran Hero
Daly Assembly
Delaney Black defiance
Devlin Fierce courage
Dillon Like a lion
Donnelly Dark, brave one
Doherty Destroyer
Doyle Dark stranger
Duffy Dark, black
Dunne Brown
Farrell Man of valor
Fay Raven
Fitzgerald Son of the spear-ruler
Flanagan Red, ruddy
Flynn Son of the red-haired one
Foley Plunderer
Foy Raven
Friel Generous, superfluous
Furey Inspired
Furlong Great man

Irish Last Names G – L

Gallagher Foreign help
Galvin Sparrow
Gannon Fair-skinned
Geary Farmer
Geraghty Noisy
Gill Servant
Gilmore Devoted to Mary
Gorman Blue
Grady Noble
Graham Warlike
Griffin Fierce
Griffith Strong lord
Guinan Little born of nobility
Hackett Little hewer of wood
Hagan Young
Haley Ingenious
Halligan Little handsome one
Hanlon Bird
Hannigan Little loved one
Harding Powerful, hardy
Harkin Dark red
Harmon Soldier
Harrington Sea tide
Hart Stag
Hartnett Strong and tough
Hayden Heathen
Healy Claimant
Heaney Little king
Heffernan Little demon
Hennessy Ancient
Herbert Illustrious warrior
Herlihy Artistic, creative
Hickey Healer
Higgins Knowledge
Hogan Young
Holland Of the manor
Holligan Healthy
Hopkins Son of Hob
Horan Chief
Howard Noble watchman
Hughes Fire
Hurley Sea tide
Hyland High land
Joyce Lord
Keegan Little fiery one
Kelly Warrior
Kennedy Ugly head
Kiernan Little dark one
King Tribute
Lacey From Lassy
Larkin Fierce
Leahy Gray speckled
Lynch Mariner

Irish Last Names M – Z

MacCarthy Son of the loving
MacDonald World ruler
MacDowell Dark stranger
MacGregor Son of the angry one
MacGuire Son of the beige one
MacIntosh Son of the chief
MacKenna Son of the handsome one
MacLoughlin Son of the Viking
MacMahon Son of the bear
MacNamara Son of the sea hound
MacNeil Son of the champion
MacPherson Son of the parson
MacQuillan Son of the cub
MacShane Son of John
Madden Little dog
Maguire Beige
Mahoney Bear
Malone Servant of St. John
Manning Monk
Martin Warlike
Mathews Gift of God
McCarthy Loving
McGuire Beige
McLoughlin Viking
McMahon Bear
McNamara Sea hound
McNeil Champion
Mooney Wealthy
Moran Big
Murphy Sea warrior
Murray Sea settlement
Nally Poor
Nolan Famous
O’Brien Exalted
O’Callaghan Bright-headed
O’Connell Strong as a wolf
O’Connor Lover of hounds
O’Donnell World ruler
O’Dowd Dark hero
O’Driscoll Interpreter
O’Farrell Man of valor
O’Flaherty Bright ruler
O’Grady Noble
O’Hara Ancient
O’Keeffe Gentle
O’Leary Keeper of calves
O’Mahoney Bear
O’Malley Chief
O’Neill Champion
O’Reilly Excessive courage
O’Rourke Champion of Ulster
O’Shea Majestic
O’Sullivan Dark-eyed
O’Toole Prosperous
Phelan Wolf
Quinn Wisdom, chief
Reilly Courageous
Ryan Little king
Scannell Scandal
Sheehan Peaceful
Sheridan Searcher
Smith Tradesman
Sullivan Dark-eyed
Walsh Welshman
Whelan Joyful
White Fair, blessed
Wilson Son of Will
Young Younger

Irish Last Names - Irish people scene

Frequently Asked Questions

What are some of the oldest Irish surnames?

There are many Irish surnames that have been in use for centuries, some of which can be traced back to the 10th century. Some of the oldest Irish surnames include O’Brien, O’Connor, O’Neill, MacCarthy, and MacMahon. These surnames were originally derived from the names of powerful clans and families that played important roles in Irish history.

What are the rarest Irish surnames?

There are many rare Irish surnames that are not as well-known as others. Some of these surnames include MacAuliffe, MacGowan, MacNulty, O’Grady, and O’Shaughnessy. These surnames are often specific to certain regions of Ireland and may have been passed down through smaller, less influential families.

It’s important to note that while some surnames may be considered rare, they are still an important part of Irish heritage and history.

Check out this video below to learn more:
https://www.youtube.com/watch?v=Hg0t-i5ws7Q

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