Tracing Irish Ancestry: Popular Irish Surnames by Region

Hiking along the Wicklow Way in the Glendalough area.

A clan, meaning family, came about as a way of uniting people of the same surname under one Kinship. Members came together under the belief they all descended from a common ancestor. For example, the O’Neills descended from one man, Niall of the Nine Hostages, who was apparently the man responsible for kidnapping St. Patrick and bringing him to Ireland. For anyone interested in the O’Neill clan, explore the ancient territory of the O’Neill’s on our Hiking the Causeway Coast & Donegal tour.

The clan’s role was to maintain and defend the native territory of their ancestors, known as a duiche. Some of the most popular clans were the McCarthy, O’Neill, O’Brien and O’Connor’s.

Each clan had various smaller septs, known as sliocht, in their Kinship. These sliocht acknowledged the supremacy of a larger clan. Examples of this are the O’Donovan’s and O’Mahoney’s, whose chiefs paid tribute to the King of the McCarthy Reagh clan of modern-day Cork. Why not travel to lands once held by the McCarthy clan on our Hiking & Island-Hopping trip?

This was how ancient Irish society was organised for centuries until Henry VIII declared himself as King of Ireland in 1542, leading to much disruption of the Gaelic social order and the eventual end of the clan system.

But all was not lost! The legacy of the clan system remains firmly imprinted in Irish life, as Irish people at home and abroad identify strongly with their family names, maintaining an in-built tribalism. So much so that in 1989 the Clans of Ireland was formed in Co. Galway to preserve the cultural history and genealogy of Irish clans. Why not check out the database yourself?

The name “Maguire,” derived from the Irish clan Mac Uidhir, first appeared in the Annals of Ulster in 956 and is said to mean “son of the brown one.” Originally a clan in the province of Leinster, the Maguires moved northwards to the beautiful Lakeland county of Fermanagh, in modern-day Northern Ireland, where they sat as kings for over 300 years. In the US, the surname Meguiar is a supposed variation of this name.

Book a private adventure through Northern Ireland’s coasts and glens to discover the beauty of the north.

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This name is mostly found in the treasured county of Donegal and roughly translates as “mighty rulers.” It’s an anglicised form of the surname “Ó Donnghaile,” meaning those with this surname are descendants of the clan namesake, “Dónal.” Other variations of the name are “Donnelly,” “O’Donnelly,” and “Donnelie,” to name a few.

The Rock of Doon near Glenveagh National Park in Donegal is the site where the O’Donnells of ancient Ireland chose to inaugurate their chieftains.

Interested in visiting the region? Explore the wilds of Donegal on a bike trip, whisking you away to the ancient seat of the O’Donnells.

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Overall, “Walsh” is the 4th most common surname in Ireland and is most plentiful in the mountainous wilds of Mayo. It was brought to Ireland by Norman/Welsh soldiers sometime during the Norman invasion of Ireland in the 12th century.

The Irish for the surname is “Breathnach,” meaning “Welshman”, and would indicate some Welsh lineage for those possessing this surname. Other variants are “Welsh,” “Welch,” “Wallis,” or “Brannagh.”

Discover the remote corners and peaks of Mayo while hiking the mountains of Connemara and Mayo.

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Supposedly the oldest recorded surname in Ireland, it derives from the Irish surname “Ó Cléirigh” – with Cleirigh meaning “clerk” or “cleric”, hinting that the Clearys of today are descendants of a learned scribe or religious man.

Today, the largest number of Clearys found outside of Ireland are located in the US state of California. A notable variation of “Cleary” is the name “Clarke.”

Bike through Galway and traditional Cleary country while cycling Ireland’s West Coast.

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Outside of Ireland, the name “O’Sullivan” is most common in England and Australia. Within Ireland, it is the third most frequently found name in the country – most popular in Kerry. There are two distinct clans: the O’Sullivan Mór of Kerry and the O’Sullivan Beara of Cork (Beara peninsula).

Both clans are known to have fought fiercely against English troops in the early 1600s alongside their allies. The name comes from the Irish O’Suileabhain and is said to mean “one-eyed” or “hawk-eyed”.

Climb to new heights and explore the region associated with the O’Sullivans on our Kerry Mountains trip.

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When you think of Butlers now, you would be forgiven for thinking of chocolate. There are 39 Butlers Chocolate cafés worldwide, with the most famous being on Grafton Street in Dublin. With the Anglo-Norman invasion of the 12th century came the name “Butler.” It derives from the Huguenot “boteillier,” meaning bottler or cupbearer.

Today it is largely found in the Marble County of Kilkenny and descendants can claim lineage from a powerful dynasty that was once known as the Dukes of Ormond.

Wander Ireland’s Ancient East on our self drive of the same name.

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In south Wicklow, nearing the end of the Wicklow Way trail, there is such an abundance of Byrnes that they must distinguish the various families by nickname – the rabbits, badgers, fish, pigs and hares, to name a few.

Identifying families by obscure nicknames is standard practice across the country, given the small population! It could be argued that “Byrne” is an anglicised version of “O’Brien,” and it likely is. But it’s one that’s taken on a life of its own.

Want more flexibility? Walk the Wicklow Way self guided to travel at your own pace.

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