Wednesday, 24 March, 2021
Share This:

Although Ireland is a relatively small country, there are many differences between each and every county – and surnames are no exception. Here are the most popular last names for every county of Ireland.

The most popular last names for every county of Ireland

Having evolved over the centuries to be the surnames we recognise today, Irish last names have a rich and vibrant history. In early times, when Ireland had a much smaller population and mass movement of people was uncommon, it was not unusual for people to be known by only one name. However, as the population began to grow in the Middle Ages, the Gaelic Clann system was established in Ireland to give people a shared identity with their people of the tribe and the area from which they came.

While many Irish surnames have evolved from Gaelic to English over hundreds of years, many traditional Irish names remain common across Ireland today. So, here are the most popular last names for every county of Ireland.

1. Antrim – Smith

Carrickfergus Castle is in County Antrim

Smith is not just Antrim’s most popular name, but it is also the most common name in Europe.

The name derives from the Old English smið or smiþ, meaning “one who works in metal”, thus indicating that the owner of this surname would have been a metal worker or blacksmith.

Do you have ancestors from County Antrim? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Antrim Ancestors

2. Armagh – Campbell

Two St Patrick's in Armagh, Ireland

The most popular surname in Armagh is Campbell, which is derived from the Gaelic terms “cam” and “beul”, meaning “crooked mouth” or “wry mouthed”.

Do you have ancestors from County Armagh? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Armagh Ancestors

3. Carlow – Mullins

Clonegal Bridge in County Carlow

An anglicised form of the Irish O’Maolain, the popular Carlow surname Mullins is thought to be derived from “maol” meaning “bald”.

Do you have ancestors from County Carlow? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Carlow Ancestors

4. Cavan – Brady

Standing stones, Cavan Burren Park, County Cavan

The Irish surname Brady is derived from the Gaelic surname Ó Brádaigh or Mac Brádaigh and means “spirited and broad”.

Do you have ancestors from County Cavan? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Cavan Ancestors

5. Clare – MacMahon

Lahinch Beach in County Clare

MacMahon, from the Old Irish Mac Mathghamhna, means “son of the bear” or “son of the bear-calf”.

Do you have ancestors from County Clare? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Clare  Ancestors

6. Cork – O’Connor

University College Cork, Cork City

One of the most popular last names for every county of Ireland, O’Connor, derives from the Gaelic Ó Conchobhair, meaning “grandson/descendant of Conchobar”.

The Irish given name Conchobhair means “lover of hounds”.

Do you have ancestors from County Cork? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Cork Ancestors

7. Derry – Bradley

Guild Hall Derry City

An English surname meaning “broad wood” or “broad meadow” in Old English, Bradley is also an anglicisation of the Gaelic Ó Brolacháin from County Tyrone.

Do you have ancestors from County Derry? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Derry Ancestors

8. Donegal – Gallagher

River Eske, Donegal Town

Gallagher has been a popular family name in Donegal since as far back as the 10th-century when the Gallagher (or Gallchobhair mac Rorcan) family ruled the Tir Chonaill county.

Do you have ancestors from County Donegal? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Donegal Ancestors

9. Down – Thompson

Saul Church in County Down

The surname Thompson is not only popular in Ireland but also across England, Scotland, and Wales.

A patronymic surname of Scottish origin, Thompson means “son of Thomas”.

Do you have ancestors from County Down? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Down Ancestors

10. Dublin – Byrne

Trinity College Dublin

In the Irish language, Byrne translates as Ó Broin and means “descendant of Bran”.

The name has been traced back as far as the ancient Celtic chieftain, Bran mac Máelmórda, King of Leinster, who was deposed in 1018.

Do you have ancestors from County Dublin? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Dublin Ancestors

11. Fermanagh – Maguire

Lough Erne, County Fermanagh

The Irish surname Maguire comes from the Gaelic Mac Uidhir, meaning “son of the dun or dark coloured one”.

Do you have ancestors from County Fermanagh? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Fermanagh Ancestors

12. Galway – Kelly

Long Walk, Galway

The popular Galway surname Kelly comes from the Gaelic O’Ceallaigh, which means “bright headed” or “troublesome”.

Do you have ancestors from County Galway? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Galway Ancestors

13. Kerry – O’Sullivan

The ring of Kerry

The surname O’Sullivan derives from the Sullivan clan, an Irish Gaelic clan based in what is today County Cork and County Kerry.

Do you have ancestors from County Kerry? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Kerry Ancestors

It is interpreted as “little dark-eyed one”.

14. Kildare – O’Toole

Grand Canal, Salins, County Kildare

The O’Tooles were historically one of the most powerful families in Leinster, and the translation of the Irish name means “descendant of the mighty people”.

Do you have ancestors from County Kildare? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Kildare Ancestors

15. Kilkenny – Brennan

Kilkenny Castle, County Kilkenny

The most popular Irish surname in Kilkenny, Brennan, is an anglicised form of three different Irish surnames: Ó Braonáin, Mac Branáin and Ó Branáin.

This patronymic surname means “son of Branán”, a personal name meaning “little raven”.

Do you have ancestors from County Kilkenny? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Kilkenny Ancestors

16. Laois – Dunne

Rock of Dunamase, County Laois

Dunne is one of the most popular last names for every county of Ireland.

This Irish surname is derived from the Irish Ó Duinn and Ó Doinn, meaning “dark” or “brown.”

Do you have ancestors from County Laois? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Laois Ancestors

17. Leitrim – Reynolds

Carrick on Shannon, County Leitrim

In Gaelic, the name Reynolds is Mac Raghnaill, which comes from the Old Norse name Rognvald.

The patronymic surname meaning “son of Reynold” derives from the given name meaning “powerful ruler”.

Do you have ancestors from County Leitrim? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Leitrim Ancestors

18. Limerick – Ryan

A View of Limerick City and the river Shannon

In some cases, Ryan is a shortened form of the patronymic name O’Ryan, an anglicised form of the Gaelic surname Ó Riain.

In Irish, Ryan is thought to mean “king”, “water”, or “ocean”, and is today among the top ten most common surnames in Ireland.

Do you have ancestors from County Limerick? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Limerick Ancestors

19. Longford – O’Reilly

Clondra Village in County Longford

O’Reilly is a name of Gaelic origin deriving from the kings of East Bréifne in what is today County Cavan.

O’Reilly is the patronymic form of the Irish name Reilly, which means “extroverted one”.

Do you have ancestors from County Longford? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Longford Ancestors

20. Louth – Matthews

Mellifont Abbey in County Longford

Matthew is a variant of the Gaelic name MacMahon, meaning “son of Matthew”.

Do you have ancestors from County Louth? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Louth Ancestors

21. Mayo – Walsh

Clew Bay in County Mayo

Walsh is an Irish surname that means “Briton”, “foreigner”, or literally “Welshman”.

It is a name that was brought to Ireland by Welsh, Cornish, and Cumbrian soldiers during and after the Norman invasion of Ireland.

Do you have ancestors from County Mayo? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Mayo Ancestors

22. Meath – O’Farrell

Newgrange in County Meath

O’Farrell is the most common Irish last name in County Meath. It derives from the Gaelic O’Fearghail, which means “man of valour”.

Do you have ancestors from County Meath? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Meath Ancestors

23. Monaghan – Connolly

Hope Castle, Muckno, County Monaghan

Connolly is the anglicised form of the Old Gaelic O’Conghaile, which means “fierce as a hound or wolf”.

Do you have ancestors from County Monaghan? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Monaghan Ancestors

24. Offaly – Hennessy

Birr Castle in County Offaly

Hennessy is the anglicised form of the Gaelic name Ó hAonghusa, which came from the Irish Kingdom of Uí Failghe or modern-day County Offally.

Do you have ancestors from County Offaly? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Offaly Ancestors

25. Roscommon – McDermott

Lough Key Park in County Roscommon

McDermott derives from the Gaelic Mac Diarmada, which means “son of Diarmuid” or “free man”.

This Irish name comes from Tadhg mac Diarmata, who was King of Connacht before the Norman invasion.

Do you have ancestors from County Roscommon? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Roscommon Ancestors

26. Sligo – McGinn

Benbulben in County Sligo

The anglicised form of the Gaelic Mag Finn, McGinn means “son of Fionn”.

Variations of the name include McGinne, Ginn, McGing, Ging, McKing, and Maginn.

Do you have ancestors from County Sligo? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Sligo Ancestors

27. Tipperary – Purcell

Rock of Cashel in County Tipperay

Purcell is an Irish name of French or Norman origin, which was given to those whose occupation was tending to pigs.

Do you have ancestors from County Tipperary? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Tipperary Ancestors

28. Tyrone – O’Neill

Hill of The O'Neill and Ranfurly House Arts Visitor Centre, Co. Tyrone

One of the most popular last names for every county of Ireland is O’Neill.

An anglicisation of the Gaelic Ua Néill, meaning “son of Niall”, an Irish name that means champion.

Do you have ancestors from County Tyrone? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Tyroone Ancestors

29. Waterford – Power

Dungarvan Harbour, County Waterford

The Irish surname Power actually derives from Norman or French origin as it was brought to Ireland during the Anglo-Norman invasion of the late 12th-century.

From the French word, povre, Power means poor or pauper.

Do you have ancestors from County Waterford? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Waterford Ancestors

30. Westmeath – Lynch

Athlone, County Westmeath

The most popular surname in Westmeath, Lynch, derives from the Gaelic Ó Loingsigh, meaning “son of Loingseach”.

The given name Loingseach means “having or belonging to a fleet of ships”, thus indicating that the owner of this name would have been a mariner or seaman.

Do you have ancestors from County Westmeath? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Westmeath Ancestors

31. Wexford – Murphy

Hook Head Lighthouse, county Wexford

One of the most well-known Irish surnames, Murphy, is the most popular last name in Wexford.

The Gaelic equivalent of this anglicised surname is Ó Murchadha, and it means “sea battler”.

Do you have ancestors from County Wexford? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Wexford Ancestors

32. Wicklow – Cullen

Guinness Lake in County Wicklow

The surname Cullen is of Gaelic origin, and it is believed to be derived from the pre-8th-century Old Gaelic name O’ Cuileannain or Ó Cuilinn, meaning “son of Cuilleannain”.

Do your Irish ancestors have any of the surnames listed above? Add their profile to the IrelandXO Ancestor Chronicles and help other descendants from the same family discover more about their Irish ancestry and the place in Ireland where they come from.

Do you have ancestors from County Wicklow? Add them to IrelandXO today and connect with other people descended from the same place.

Tell us about your Wicklow Ancestors