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The Origins And Meanings Of Common Irish Last Names

Image Restoration Center Blog Logo

The Origins And Meanings Of Common Irish Last Names

Irish people were some of the first people in Europe to use last names, which means that many Irish last names, even common ones, have a long and storied past. Your last name could clue you into where your ancestors came from or what they were like. 

Looking to learn more about your family history? Your surname is an excellent place to start. If you are of Irish heritage, this article should give you some context and background about your Irish last name.

History Of Surnames In Ireland

The first surname in Ireland was used in the year 916, before most of Europe started to adopt surnames. While nobles were using surnames from the 900s, it wasn’t until the 1500s that they became popular enough to be used among the common folk.

houses in ireland

The First Surnames

Irish last names started to show up around the 10th century. The death of the lord of Aidhne, Tigherneach Ua Cleirigh, was recorded. “Ua Clerigh” was the lord’s surname, which has since evolved into O’Clery. It’s one of the oldest surnames in Europe.

Before surnames, Irish people would use patronymics, like the Scandinavians. For example, Sweeney, son of Donald, would be named Sweeney MacDonald, while his sons would be MacSweeney and his daughters would be Nic Sweeney. The name would change with every generation, so there weren’t permanent family names in Ireland.

Sometimes, grandchildren would take their grandparents’ names. If a prominent family member was named Niall, the prefix “O” could also be used, meaning “descendant of”. “Ua” is an older form of the prefix “O”, and some older Irish document names use “Ua”. For example, a grandson or descendant of an important “Niall” would take the surname “O’Neil”, which is derived from the name “Niall”.

Foreign Invaders Bring Their Names

Surnames also reflect the waves of invasion that washed over the Emerald Isle. Two major colonizers influenced Irish surnames: the Normans and the English.

The arrival of the Norman invaders brought surnames with the prefix “Fitz” to Ireland, like “Fitzgerald” or “Fitzpatrick”. It is the Norman version of a patronymic. If your name starts with a “de” or “le” but your family is Irish, then that name comes from their influence as well. Examples of Norman Irish names are “Lehane” and “Delaney”.

The English brought with them Anglicized versions of Irish names. When the English came, it became disadvantageous to have a very Irish-sounding name. Thus, many Irish people changed their names to reflect their colonizer’s culture. Names like “Ó Cathasaigh” became “O’Casey” and “MacGabhann” became “McGowan” or even “Smith”, the Anglicized version of the Irish “Gabhann” or “Gowan”, which means “smith”.

dublin bridge

Origins Of Irish Surnames

Irish surnames are derived from multiple sources – the most common ones are nicknames and family members. Surnames that come from the area or town a person lives or their occupation are a little rarer.

Below are the typical origins of common Irish last names.

Characteristic Surnames

This type of surname comes from an ancestor who had a nickname or particular trait that was memorable. For example, the Duffs probably had a dark-featured ancestor, as “duff” is an Irish word for “dark”. The Sullivans probably also had a dark-eyed ancestor, as “Sullivan” means “dark-eyed”. Another example is “O’Casey”, which means “watchful” or “vigilant”.

Patronymic Surnames

Patronymics are last names derived from a male ancestor and make up some of the most common surnames in Ireland. The addition of “Mac” or “O” to a first name makes it a surname, so almost any Irish name has the potential to be patronymic. “Mac” means “son of”, and “O” is a prefix that means “descendant” or “offspring”.

The most common patronymics start with “Mac” or “O”, but some also start with “Fitz”. This style of patronymic was brought over by the Normans and was derived from the French word “fils”, meaning “son”. Thus, “Fitzpatrick” means “son of Patrick”.

Occupational Surnames

Occupational surnames are names that come from jobs. For example, the first Irish surname, “O’Clery”, came from the word for “clerk”. Despite one of the first surnames falling under this category, occupational Irish last names are rare.

Toponymic Surnames

This kind of surname is taken from the name of a place. This could be the seat of a noble family or simply where someone comes from. This type of name is also rare in Ireland.

street view ireland

The Most Popular Irish Surnames

Here is a list of some of the most common last names in Ireland and their meanings. Check them out and see if your name is on the list!

  1. Murphy: The most popular Irish last name, it means “sea warrior”. It’s the English version of the original Irish name “Mac Murchadha” or “Ó Murchadha”.
  2. Kelly: This name comes from the original Irish “Ó Ceallaigh”. The name means “warrior”, “one who frequents churches”, or “bright-headed”. 
  3. O’Sullivan: This name comes from the Irish “Ó Súilleabháin” or “Ó Súileabháin”. “Sullivan” means “dark-eyed”. 
  4. Walsh: This Irish surname means “Welsh” or “of Welsh descent” and is one of the few toponymic names in Ireland. The Norman invasion brought this name to Ireland. 
  5. Smith: An occupational surname, Smith is an Anglicized version of “Gabhann”. While it sounds English, it can also be the surname of people with Irish heritage.
  6. O’Brien: A Patronymic name, “O’Brien” comes from King Brian Boru of Munster. 
  7. Byrne: This name could mean either “raven” or “son of Broin”, from the original Irish last name Ó Broin. It is said to have stemmed from Bran mac Máelmórda, a Celtic King of Leister.
  8. Ryan: The surname “Ryan” has a few possible sources. It could have been derived from three possible names: “Ó Maoilriain”, which is “offspring of Maoilriaghain”; “Ó Riagháin”, which means “offspring of Rían”; or “Ó Ruaidhín”, meaning “offspring of the small red one”, so the name is either patronymic or characteristic. This name could also be a shortened version of “Mulryan”, which is a way to say “small king”.
  9. O’Connor: The descendant of Connor, meaning “lover of dogs”.
  10. O’Neill: This is a patronymic name meaning “son of” or “offspring of Niall”. “Niall” means “vehement” or “champion”.
  11. O’Reilly: This name is a patronymic coming from the Irish name “O’Raghaillach”. It is said that Raghaillach was a famed warrior who fought alongside Brian Boru. 
  12. Doyle: Originally “O’Doyle”, “Doyle” is a patronymic surname meaning “descendant of Dubhghall”.
  13. McCarthy: “McCarthy” comes from one of the more prominent Celtic families from before the English invasion. It is patronymic and means “descendant of Carthach”, where “Carthach” means “loving”.
  14. Gallagher: A patronymic surname derived from an ancestor named “Gallchobhar”. The name means “foreign” or “support”.
  15. O’Doherty: Another patronymic name, “O’Doherty” means “descendant of Dochartach”, a name that means “the destroyer”. 
  16. Kennedy: This is an Irish name meaning “helmeted chief” or “leader”. The most prominent “Kennedy” is the late American President John F. Kennedy.
  17. Lynch: This name was derived from “Ó Loingsigh”, meaning “having a fleet of ships”. It can also be Anglicized as “Lindsay”, “Lynsky”, or “Lynchy”. 
  18. Murray: This is a historical and toponymic surname. It means that the bearer comes from Moray, a small historical kingdom that sits near Scotland.
  19. Quinn: Coming from “O’Cuinn”, this name could mean “descendant of Con”, “leader”, or “intelligence”. It is derived from the word “ceann”, which means “head”.
  20. Moore: This name comes from the old Irish “O’Mordha”, which means “stately” and “noble”.

Closing Thoughts

You might think that your common last name has little to tell you about your history, but there is so much that you can learn from it. Every last name has a rich story behind it, and last names from Ireland have gone through many changes and iterations. 

Your family history is very important, as learning where you came from can help you get in touch with who you are. You might even have heroic ancestors or grand relatives in your family tree! We hope this post has encouraged you to look into your family name – you never know what you might find.