Ireland has a rich history and culture, with surnames that tell the story of its people. Irish surnames originated from patronymic, occupational, descriptive, and ancestral origins. When the English conquered Ireland, many Gaelic Irish names were anglicized into similar sounding English names. This means that many Irish names have English versions today. So what is the most common Irish surname? Here is a quick overview of the top Irish last names and their histories.
Quick Answer: Murphy
The most common Irish last name is Murphy. Murphy originated as the anglicized version of the Gaelic names MacMurchadha and Ó Murchadha, derived from the Irish word for sea warrior. The Murphy surname is particularly common in County Wexford and County Cork. It rose to popularity in the 19th century during the Irish potato famine, as many Irish emigrants adopted anglicized versions of their names as they settled in English-speaking countries like America, Canada, and Australia.
Tracing the History of Irish Surnames
The use of fixed hereditary surnames came to Ireland later than in other European countries. Prior to the 10th century, the Irish typically used simple descriptive names related to family descent. For example, Niall Glúndubh meant “Niall of the black knee.” The earliest Irish surnames were patronymic, adding the prefix “Mac” meaning “son of” or “Ó” meaning “grandson of” to a paternal ancestor’s name. For instance, Mac Murrough indicated “son of Murrough” and Ó Crean indicated “grandson of Crean.”
As the Anglo-Norman conquest of Ireland introduced feudalism in the 12th century, the use of patronymic surnames faded among the Gaelic Irish. By the 15th century, patrilineal and matrilineal surnames became hereditary. During English rule in the 16th and 17th centuries, many Gaelic Irish names were anglicized into similar sounding English surnames, often removing the “Mac” or “Ó” prefix. For example, Ó Cuinn became Quinn and Mac Aodhagáin became Mackeown. This assimilation explains why many common modern Irish surnames have an English sound.
The Most Common Irish Surnames
According to genealogy records, census rankings, and polls, these are among the most widespread Irish last names today:
1. Murphy
As already mentioned, Murphy is the most common Irish surname, with an estimated population of 279,000 people bearing the name. It originates from two Gaelic surnames – Mac Murchadha and Ó Murchadha – denoting the Irish word for “sea warrior.” Murphy is particularly prevalent in Counties Wexford and Cork. Notable Murphys include actor Cillian Murphy and rock musician Peter Murphy.
2. Kelly
Kelly is the second most common Irish last name, shared by around 250,000 people worldwide. It stems from the Gaelic Ó Ceallaigh, denoting descendants of Ceallach, an early 10th century Irish king. Kelly arose independently in England and Scotland from similar sources. Well-known people with the Kelly surname include actress Grace Kelly and musician R. Kelly.
3. O’Sullivan
O’Sullivan is the third most widespread Irish name, with an estimated population of 121,000. It originates from the Gaelic Ó Súilleabháin, denoting “descendent of the dark-eyed one.” The name refers to an 11th century Munster king renowned for his keen eyes. Notables with the O’Sullivan name include actor Barry Sullivan and columnist Maureen O’Sullivan.
4. Walsh
Walsh is another common Irish surname, shared by around 113,000 people. It arose as the English version of Breathnach, derived from the Old Irish word Brécnach meaning “from Wales” or “foreigner” – denoting Anglo-Norman settlers. The Walsh name is particularly prevalent in counties Mayo, Wexford, Galway, and Kilkenny. Notable Walshes include actress Kate Walsh and author Mary Ellen Walsh.
5. O’Brien
O’Brien is estimated to be among the top 10 most common Irish surnames, with over 104,000 bearers worldwide. It comes from the Gaelic Ó Briain meaning “of Brian,” referring to the High King Brian Boru who thwarted Viking conquests in Ireland. O’Brien is common in County Clare due to associations with Brian Boru’s ancestral homeland. Well-known O’Briens include Conan O’Brien and Soledad O’Brien.
6. Byrne
Byrne is another very common Irish name, borne by some 94,000 people worldwide. It derived from the Gaelic name Ó Broin, referring to descendents of Bran – an ancient king of Leinster. The name is prevalent in Counties Wicklow and Dublin. Notable people with the surname Byrne include actress Rose Byrne and musician David Byrne.
7. Ryan
Ryan is a widespread Irish surname with over 84,000 holders. It comes from the Old Irish Ó Riagháin, meaning “descendent of Rian.” Though the precise origin of Rian is uncertain, theories say it means “water” or “little king.” Popular figures with the Ryan name include actors Meg Ryan and Ryan Reynolds.
8. O’Connor
O’Connor is another very prevalent Irish last name, shared by some 80,000 people worldwide. It arose from the Gaelic Ó Conchobhair meaning “patron of warriors.” The name has origins in an ancient Irish kingdom, with many O’Connors of royal descent. Notable O’Connors include singer Sinead O’Connor and actor Carroll O’Connor.
9. Smith
Smith is among the top 10 most common surnames in Ireland, with around 77,000 bearers. Though not Gaelic, it became well established from tradesmen and blacksmiths during the Middle Ages. Smith later grew more common in Ireland from English and Scottish migration. Famous people with the surname include Maggie Smith and Will Smith.
10. Doyle
Doyle is the last Irish name on the top 10 list, shared by about 76,000 people worldwide. It derived from the Gaelic Ó Dubhghaill, referring to descendents of Dubhghall, meaning “dark stranger” or “troublesome.” Doyle is popular in Leinster and Munster. Notable Doyles include author Sir Arthur Conan Doyle and actor Peter Doyle.
Other Notable Irish Surnames
Beyond the top 10 Irish names, other common surnames from Ireland include:
- Campbell
- Clarke
- Collins
- Cooper
- Cunningham
- Doherty
- Donnelly
- Duffy
- Fitzgerald
- Flynn
- Gallagher
- Kennedy
- Lynch
- McCarthy
- McDonald
- McLaughlin
- Moore
- Murray
- Nolan
- O’Connor
- O’Leary
- O’Neill
- Quinn
- Reilly
- Stewart
- Sullivan
- Thompson
- White
While they may not make the top 10 list, these names still have rich Irish histories and notable bearers worldwide.
The Origins and Meanings of Irish Surnames
Examining the origins and meanings of Irish last names provides a window into the country’s cultures and ancestors. Irish surnames broadly fall into four categories:
1. Patronymic & Family Names
Many common Irish surnames arose as patronyms, created from male given names with the addition of a prefix or suffix denoting “descendant.” For example, “Fitz” means “son of” and “O” means “grandson/descendent of.” Examples include Fitzgerald (“son of Gerald”) and O’Brien (“grandson of Brien”). Over time, patronymic names became fixed hereditary surnames passed down through generations of the same family.
2. Adopted Clan Names
Some Irish last names derive from the name of a clan or sept – families or groups who shared a common surname and allegiance. Many adopted the surname of powerful clans such as the Uí Néill and Uí Briain to gain favor and assimilate. For instance, the common surname O’Neill comes from the powerful Uí Néill clan.
3. Gaelic Origins
Many Irish names come directly from the Gaelic language. For example, the surname Brennan comes from Ó Braonáin meaning “descendant of Braonán” – where “Braonán” means “sorrow.” Other names have Gaelic origins describing ancestors’ physical features, personality traits, occupations, or homeplace names.
4. Anglicized & Translated Names
After the Norman conquest, many Gaelic Irish names were anglicized into similar English versions. For example, De Paor became Power. Some translations also stem from the Vikings, such as Mac Giolla Mhuire becoming Fitzpatrick (“son of the devotee of Mary”).
The Regional Distribution of Irish Surnames
While many Irish names are common nationwide, certain surnames have strong regional associations based on ancestral clans and septs. Here is an overview of the geographic spread of common Irish last names:
| Surname | Region |
|---|---|
| Murphy | Wexford, Cork |
| Kelly | Nationwide |
| O’Sullivan | Cork, Kerry |
| Walsh | Mayo, Wexford, Galway, Kilkenny |
| O’Brien | Clare, Limerick |
| Byrne | Wicklow, Dublin |
| Ryan | Tipperary, Limerick |
| O’Connor | Offaly, Roscommon |
| Doyle | Wexford, Carlow |
| Fitzgerald | Munster |
This table summarizes the counties where some of the top Irish surnames originated and remain most common today due to ancestral roots.
The Impact of Irish Surname Emigration
Through large-scale 19th century emigration from Ireland to countries like America, Canada, Australia and beyond, common Irish surnames became well established worldwide. Fleeing conflict, famine and poverty, it’s estimated over 4.5 million Irish emigrated following the Great Famine of the 1840s.
Today, Irish last names permeate the top surname rankings of many English-speaking countries, especially in the United States, where 10% of the population claim Irish descent. For instance, Murphy is the 9th most common U.S. surname, Kelly is 11th, Sullivan is 13th, and other Irish names like Ryan, Doyle, McCarthy and Gallagher rank in the top 50.
Beyond preserving Ireland’s cultural legacy worldwide, the global diaspora of signature Irish surnames reflects the country’s ancestral ties across continents through kith and kin.
Conclusion
Irish surnames provide a living link to the Emerald Isle for over 70 million people worldwide who claim Irish ancestry. Common Irish names like Murphy, Kelly, O’Sullivan, Walsh, and O’Brien have rich histories connecting the generations to ancestors in Ireland dating back centuries. While surnames originated as ways to identify family lineages starting in the 10th century, today they unite the global Irish diaspora.
Examining Irish names gives insight into the country’s diverse cultures, clans, ancestors, and Gaelic language. Though many names became anglicized over time, their Irish roots largely endure. The enduring popularity and spread of quintessential Irish last names pays homage to the long legacy and cultural contributions of the Irish worldwide.