Irish last names carry centuries of history, family traditions, occupations, places, and Gaelic culture. Some surnames are instantly recognizable, while others have fascinating meanings that reveal something about the people who first used them. Whether you are researching your Irish family history, choosing a surname for a character, exploring your heritage, or simply curious about Irish surnames, there is plenty to discover.
This guide to Irish last names brings together traditional, popular, rare, and distinctive surnames with their meanings and cultural origins. You will find names connected to Gaelic clans, ancient occupations, geography, personal characteristics, and patronymic traditions.
Irish surnames can also appear in several spellings because names changed over time as Gaelic names were translated, Anglicized, or recorded differently. Therefore, a modern spelling may look quite different from its original Irish form.
Below, you can explore carefully selected Irish family names and learn what makes each one special.
Fun Fact About Irish Last Names
Many Irish surnames began as patronymic names, meaning they identified a person through a male ancestor. Prefixes such as Ó, meaning “descendant of,” and Mac, meaning “son of,” became important parts of traditional Irish naming. Over generations, these names were often Anglicized, creating familiar forms such as O’Brien, O’Connor, McCarthy, and MacMahon that remain widely recognized today.
Traditional Irish Last Names With Deep Gaelic Roots
Traditional Irish surnames often preserve connections to old Gaelic families and medieval Ireland. Many developed from personal names belonging to an ancestor, while others became associated with powerful clans and territories.
When researching an old Irish family name, remember that spelling can vary. Historical records were often written by English-speaking officials who recorded Gaelic names according to pronunciation.
The table below includes surnames with strong connections to traditional Irish naming history. These choices work particularly well when you want a surname that feels authentically rooted in Irish culture rather than simply sounding Irish.
| Name | Meaning | Origin |
| O’Brien | Descendant of Brian | Irish Gaelic |
| O’Connor | Descendant of Conchobar | Irish Gaelic |
| O’Neill | Descendant of Niall | Irish Gaelic |
| O’Donnell | Descendant of Domhnall | Irish Gaelic |
| O’Sullivan | Descendant of Súilleabhán | Irish Gaelic |
| O’Rourke | Descendant of Ruarc | Irish Gaelic |
| O’Carroll | Descendant of Cearbhall | Irish Gaelic |
| O’Callaghan | Descendant of Ceallachán | Irish Gaelic |
| O’Flaherty | Descendant of Flaithbheartach | Irish Gaelic |
| O’Grady | Descendant of Gráda | Irish Gaelic |
| O’Dwyer | Descendant of Duibhir | Irish Gaelic |
| O’Dea | Descendant of Déaghaidh | Irish Gaelic |
| O’Keefe | Descendant of Caomh | Irish Gaelic |
| O’Mahony | Descendant of Mathghamhain | Irish Gaelic |
| O’Leary | Descendant of Laoghaire | Irish Gaelic |
| O’Malley | Descendant of Máille | Irish Gaelic |
| O’Donovan | Descendant of Donndubhán | Irish Gaelic |
| O’Driscoll | Descendant of Driscoll | Irish Gaelic |
| O’Farrell | Descendant of Fearghal | Irish Gaelic |
| O’Hara | Descendant of Eaghra | Irish Gaelic |
Popular Irish Last Names You See Today
Some Irish surnames have become especially familiar because Irish communities spread throughout Britain, North America, Australia, and other parts of the world. Immigration, family connections, and historical migration helped Irish family names become globally recognizable.
A popular surname can still have a fascinating history. Names may have several regional forms, and the same surname can be associated with different branches of an extended family.
If you are choosing an Irish surname for a story, family project, or fictional character, popular names can be useful because readers usually recognize them immediately. However, checking the historical meaning helps you choose one that fits your character or purpose.
| Name | Meaning | Origin |
| Murphy | Descendant of Murchadh | Irish Gaelic |
| Kelly | Descendant of Ceallach | Irish Gaelic |
| Ryan | Descendant of Rían | Irish Gaelic |
| Byrne | Descendant of Bran | Irish Gaelic |
| Walsh | Welshman or person of Welsh origin | Irish |
| Doyle | Descendant of Dubhghall | Irish Gaelic |
| Kennedy | Descendant of Cennétig | Irish Gaelic |
| Gallagher | Descendant of Gallchobhair | Irish Gaelic |
| Fitzpatrick | Son of Patrick | Anglo-Irish |
| Brennan | Descendant of Braonán | Irish Gaelic |
| Quinn | Descendant of Conn | Irish Gaelic |
| Burke | From de Burgh family | Anglo-Norman Irish |
| Lynch | Descendant of Loingseach | Irish Gaelic |
| Murray | Descendant of Muireadhach | Irish Gaelic |
| Collins | Descendant of Coileán | Irish Gaelic |
| McCarthy | Son of Cárthach | Irish Gaelic |
| McMahon | Son of Mathghamhain | Irish Gaelic |
| McGrath | Son of Gráda | Irish Gaelic |
| Sullivan | Anglicized Súilleabhán | Irish Gaelic |
| Connolly | Descendant of Conghal | Irish Gaelic |
Irish Last Names Beginning With O
The prefix O’ is one of the most recognizable features of Irish surnames. It comes from the Gaelic Ó, traditionally meaning “descendant of.” Historically, it connected an individual with a male ancestor whose personal name formed the foundation of the family surname.
Not every modern surname that once had an O-prefix still uses the apostrophe. Spelling and family preferences changed over different periods, especially during Anglicization.
These surnames are useful when you specifically want an Irish family name with a strong Gaelic appearance. They also offer a wide variety of sounds, from short names such as O’Dea to longer choices such as O’Shaughnessy.
| Name | Meaning | Origin |
| O’Shaughnessy | Descendant of Seachnasaigh | Irish Gaelic |
| O’Quinn | Descendant of Conn | Irish Gaelic |
| O’Riley | Descendant of Raghailleach | Irish Gaelic |
| O’Boyle | Descendant of Baoigheall | Irish Gaelic |
| O’Clery | Descendant of Cleirigh | Irish Gaelic |
| O’Gorman | Descendant of Gormán | Irish Gaelic |
| O’Higgins | Descendant of Uigín | Irish Gaelic |
| O’Kane | Descendant of Cathán | Irish Gaelic |
| O’Loughlin | Descendant of Lochlann | Irish Gaelic |
| O’Meara | Descendant of Meadhra | Irish Gaelic |
| O’Moran | Descendant of Mórán | Irish Gaelic |
| O’Moore | Descendant of Mórdha | Irish Gaelic |
| O’Riordan | Descendant of Rioghbhardan | Irish Gaelic |
| O’Rooney | Descendant of Ruadhán | Irish Gaelic |
| O’Shea | Descendant of Séaghdha | Irish Gaelic |
| O’Toole | Descendant of Tuathal | Irish Gaelic |
| O’Tierney | Descendant of Tighearnach | Irish Gaelic |
| O’Tracy | Descendant of Treasach | Irish Gaelic |
| O’Byrne | Descendant of Bran | Irish Gaelic |
| O’Doherty | Descendant of Dochartaigh | Irish Gaelic |
Irish Last Names Beginning With Mc and Mac
Mac is a Gaelic patronymic element traditionally meaning “son of.” In Ireland, it appears in numerous surnames, although spelling has changed across historical documents and regions.
The forms Mac, Mc, and sometimes other Anglicized spellings can refer to related naming traditions. However, it is important not to assume that every surname beginning with Mc has exactly the same family history. Different families could develop similar-looking names independently.
These surnames are particularly useful if you are looking for a strong, traditional family-name style. They also represent the influence of Gaelic naming customs that survived through centuries of social and linguistic change.
| Name | Meaning | Origin |
| MacNamara | Son of Cú Na Mara | Irish Gaelic |
| MacDermott | Son of Diarmaid | Irish Gaelic |
| MacDonagh | Son of Donnchadh | Irish Gaelic |
| MacDonell | Son of Domhnall | Irish Gaelic |
| MacDougall | Son of Dubhghall | Scottish Gaelic/Irish |
| MacEvoy | Son of Aodh Bhuí | Irish Gaelic |
| MacFadden | Son of Páidín | Irish Gaelic |
| MacGowan | Son of the smith | Irish Gaelic |
| MacInerney | Son of Inneirghe | Irish Gaelic |
| MacKenna | Son of Cionaoith | Irish Gaelic |
| MacLaughlin | Son of Lochlann | Irish Gaelic |
| MacManus | Son of Manus | Irish Gaelic |
| MacNally | Son of Niall | Irish Gaelic |
| MacShane | Son of Seán | Irish Gaelic |
| MacSorley | Son of Somhairle | Gaelic |
| MacTavish | Son of Thomas | Gaelic |
| MacTiernan | Son of Tighearnán | Irish Gaelic |
| MacAuley | Son of Amhlaoibh | Irish Gaelic |
| MacBride | Son of Brighid | Irish Gaelic |
| MacCabe | Son of Cabe | Irish Gaelic |
Rare Irish Last Names With Unique Meanings
Rare Irish surnames can be especially interesting because they may preserve regional traditions or older forms that are less common today. Some originated from personal names, while others developed from occupations, nicknames, or geographical descriptions.
When selecting a rare Irish surname, avoid assuming that “rare” automatically means “ancient.” A surname may be uncommon today because a particular family branch remained geographically limited, changed its spelling, or adopted another form.
For genealogy, rare names can sometimes make research easier because fewer unrelated families share them. Even so, historical records should be checked carefully before connecting a surname to a specific ancestral line.
| Name | Meaning | Origin |
| Hegarty | Descendant of Eachthigheirn | Irish Gaelic |
| Hennessy | Descendant of Aonghus | Irish Gaelic |
| Hynes | Descendant of Aonghus | Irish Gaelic |
| Kelleher | Descendant of Ceallachair | Irish Gaelic |
| Kinsella | Descendant of Cinnsealach | Irish Gaelic |
| Loughrey | Descendant of Lochraighe | Irish Gaelic |
| Muldowney | Descendant of Maoldomhnaigh | Irish Gaelic |
| Mulrooney | Descendant of Maolruanaidh | Irish Gaelic |
| Naughton | Descendant of Neachtain | Irish Gaelic |
| Phelan | Descendant of Faolán | Irish Gaelic |
| Prendergast | From Prendergast family | Anglo-Norman Irish |
| Sheehan | Descendant of Síodhachán | Irish Gaelic |
| Tierney | Descendant of Tighearnach | Irish Gaelic |
| Tuohy | Descendant of Tuathal | Irish Gaelic |
| Whelan | Descendant of Faolán | Irish Gaelic |
| Callinan | Descendant of Callinán | Irish Gaelic |
| Coughlan | Descendant of Cochlán | Irish Gaelic |
| Flannery | Descendant of Flannabhra | Irish Gaelic |
| Gormley | Descendant of Gormghal | Irish Gaelic |
| Molloy | Descendant of Maolmhuadh | Irish Gaelic |
Irish Last Names Inspired by Nature and Landscapes
Ireland’s landscape has influenced its language, stories, and family names for generations. Although many Irish surnames are patronymic, some connect more directly with physical surroundings, colors, animals, or descriptions.
These names can be appealing if you want a surname with a natural or poetic quality. They also work well for fictional characters because the meanings can suggest personality, setting, or family background without being too obvious.
However, surname meanings can be complicated. A modern English translation may simplify an older Gaelic word, so treat translations as helpful interpretations rather than perfect one-word definitions.
| Name | Meaning | Origin |
| Cullen | Descendant of Coileán; associated with “holly” | Irish Gaelic |
| Rowan | Descendant of Ruadhán; linked with red-haired ancestor | Irish Gaelic |
| Doyle | Descendant of Dubhghall, “dark stranger” | Irish Gaelic |
| Duff | Dark or black | Gaelic |
| Dunn | Brown or dark | Irish Gaelic |
| Flynn | Descendant of Flann, “red or ruddy” | Irish Gaelic |
| Greene | Green or living near green land | English-Irish |
| Joyce | From Gaelic Seóighe | Anglo-Irish |
| Nolan | Descendant of Nuallán | Irish Gaelic |
| Reilly | Descendant of Raghailleach | Irish Gaelic |
| Roche | Rock or rocky place | Anglo-Norman Irish |
| Ross | Headland or promontory | Gaelic |
| Sweeney | Descendant of Suibhne | Irish Gaelic |
| White | Fair-haired or pale | English-Irish |
| Woods | Person living near woods | English-Irish |
| Dale | Valley dweller | English-Irish |
| Ford | Dweller near a river crossing | English-Irish |
| Heath | Person living near heathland | English-Irish |
| Moore | Moorland dweller | English-Irish |
| Reed | Red-haired or reed-associated | English-Irish |
Irish Occupational Last Names
Some surnames developed from the work an ancestor performed. Occupational surnames were useful because they distinguished people who shared the same personal names.
Ireland’s traditional economy included farming, craftsmanship, metalworking, fishing, and other trades. As these occupations became associated with families, occupational descriptions could eventually become hereditary surnames.
If you are writing historical fiction, an occupational surname can add subtle background to a character. Still, remember that the modern surname does not necessarily mean the family continues to practice the original occupation.
| Name | Meaning | Origin |
| Smith | Metalworker or blacksmith | English-Irish |
| Joyce | Gaelicized form associated with Seóighe | Anglo-Irish |
| Carpenter | Woodworker | English-Irish |
| Cooper | Barrel maker | English-Irish |
| Fletcher | Arrow maker | English-Irish |
| Fisher | Fisherman | English-Irish |
| Miller | Mill worker or miller | English-Irish |
| Baker | Bread maker | English-Irish |
| Butler | Household officer | Anglo-Norman Irish |
| Cooke | Cook or food preparer | English-Irish |
| Farmer | Agricultural worker | English-Irish |
| Gardiner | Gardener | English-Irish |
| Harper | Harp player | English-Irish |
| Mason | Stoneworker | Anglo-Norman Irish |
| Porter | Gatekeeper or carrier | English-Irish |
| Shepherd | Keeper of sheep | English-Irish |
| Taylor | Tailor | English-Irish |
| Thatcher | Roof thatcher | English-Irish |
| Weaver | Textile worker | English-Irish |
| Wright | Craftsman or maker | English-Irish |
Irish Last Names With Norman and Anglo-Irish Roots
Not every Irish surname comes directly from Gaelic Ireland. The arrival of Anglo-Norman families in Ireland introduced new surnames, several of which eventually became deeply connected with Irish history.
Over time, many families of Norman origin adopted Irish customs, language, and identities. This process means that a surname can have Norman or English roots while still being an important part of Irish heritage.
These names are useful when exploring the broader story of Irish surnames. Ireland’s naming history is not limited to one linguistic source; it reflects centuries of cultural interaction.
| Name | Meaning | Origin |
| Fitzgerald | Son of Gerald | Anglo-Norman |
| FitzGerald | Son of Gerald | Anglo-Norman |
| Fitzsimons | Son of Simon | Anglo-Norman |
| Fitzsimmons | Son of Simon | Anglo-Norman |
| Fitzgibbon | Son of Gilbert | Anglo-Norman |
| Fitzmaurice | Son of Maurice | Anglo-Norman |
| Fitzwilliam | Son of William | Anglo-Norman |
| Fitzgeralds | Family of Fitzgerald | Anglo-Norman Irish |
| Butler | Household official | Anglo-Norman |
| Devereux | From Évreux | Norman |
| Dillon | From Dilun | Anglo-Norman Irish |
| Dalton | From Dalton | Anglo-Norman Irish |
| D’Arcy | From Arcy | Anglo-Norman Irish |
| Grace | From de Gratia | Anglo-Norman Irish |
| Plunkett | From Plunkett family | Anglo-Norman Irish |
| Talbot | Heraldic family name | Anglo-Norman Irish |
| Nugent | From Nogent | Anglo-Norman Irish |
| Bermingham | From Birmingham | Anglo-Norman Irish |
| Preston | From Preston | Anglo-Norman Irish |
| Savage | Personal nickname or family name | Anglo-Norman Irish |
Irish Last Names Connected to Clan Heritage
Irish clans played an important role in medieval and early modern society. A clan could include extended family groups and people connected through allegiance, territory, or ancestry.
Today, people often use “clan” in a broader cultural sense. A surname can suggest a historical association without proving that every person with that surname belongs to one particular ancient clan.
If you are researching your ancestry, use the surname as a starting point rather than final evidence. Parish records, birth certificates, census documents, immigration records, and family documents can provide much stronger connections between generations.
| Name | Meaning | Origin |
| MacCarthy | Son of Cárthach | Irish Gaelic |
| O’Neill | Descendant of Niall | Irish Gaelic |
| O’Donnell | Descendant of Domhnall | Irish Gaelic |
| O’Brien | Descendant of Brian | Irish Gaelic |
| O’Sullivan | Descendant of Súilleabhán | Irish Gaelic |
| O’Connor | Descendant of Conchobar | Irish Gaelic |
| O’Rourke | Descendant of Ruarc | Irish Gaelic |
| O’Carroll | Descendant of Cearbhall | Irish Gaelic |
| O’Kelly | Descendant of Ceallach | Irish Gaelic |
| O’Mahony | Descendant of Mathghamhain | Irish Gaelic |
| O’Doherty | Descendant of Dochartaigh | Irish Gaelic |
| O’Gallagher | Descendant of Gallchobhair | Irish Gaelic |
| O’Farrell | Descendant of Fearghal | Irish Gaelic |
| O’Byrne | Descendant of Bran | Irish Gaelic |
| O’Foley | Descendant of Foghladh | Irish Gaelic |
| O’Gara | Descendant of Odhar | Irish Gaelic |
| O’Healy | Descendant of Éalaidhe | Irish Gaelic |
| O’Malley | Descendant of Máille | Irish Gaelic |
| O’Madden | Descendant of Madadhán | Irish Gaelic |
| O’Scanlon | Descendant of Scannlán | Irish Gaelic |
Irish Last Names With Strong Historical Character
Some surnames immediately create a sense of history because they are associated with old Gaelic personal names, medieval families, or distinctive Irish spellings.
These names can be particularly effective for novels, historical fiction, genealogy projects, fantasy characters inspired by Ireland, and family-history research. Their meanings also provide useful clues about the naming traditions behind them.
When using a historical Irish surname for fiction, pronunciation matters less than consistency unless the story specifically focuses on Irish language and culture. For real genealogy, however, researching the original Gaelic form can reveal valuable information.
| Name | Meaning | Origin |
| Brannigan | Descendant of Branagán | Irish Gaelic |
| Cavanagh | Descendant of Caomhán | Irish Gaelic |
| Creighton | Settlement or estate name | Anglo-Irish |
| Donnelly | Descendant of Donnghaile | Irish Gaelic |
| Egan | Descendant of Aodhagán | Irish Gaelic |
| Finnegan | Descendant of Fionnagán | Irish Gaelic |
| Hanley | Descendant of Annla | Irish Gaelic |
| Keane | Descendant of Cathán | Irish Gaelic |
| Keating | Descendant of Céitinn | Irish Gaelic |
| Kilpatrick | Church of Patrick | Gaelic/Anglo-Irish |
| Lennon | Descendant of Leannán | Irish Gaelic |
| Larkin | Descendant of Lorcán | Irish Gaelic |
| Madden | Descendant of Madadhán | Irish Gaelic |
| Moran | Descendant of Mórán | Irish Gaelic |
| Rafferty | Descendant of Raghartach | Irish Gaelic |
| Regan | Descendant of Riagán | Irish Gaelic |
| Sheridan | Descendant of Sirideán | Irish Gaelic |
| Shaughnessy | Descendant of Seachnasaigh | Irish Gaelic |
| Tobin | Descendant of Tóibín | Anglo-Norman Irish |
| Treacy | Descendant of Treasach | Irish Gaelic |
Irish Last Names That Make Great Character Surnames
If you are choosing an Irish surname for a fictional character, focus on the feeling you want the name to create. A short surname can sound modern and memorable, while a longer Gaelic-derived name may give a character a more traditional or historical identity.
You can also pair a surname with the character’s location, age, personality, and background. Avoid choosing a name solely because its translated meaning sounds attractive; surname meanings often describe an ancestor rather than the person who carries the name today.
The following options provide different sounds and historical associations, making them useful for novels, games, role-playing characters, and creative projects.
| Name | Meaning | Origin |
| Ahern | Descendant of Eachthigheirn | Irish Gaelic |
| Bannon | Descendant of Bánán | Irish Gaelic |
| Berrigan | Descendant of Berrigán | Irish Gaelic |
| Boland | Descendant of Bólland | Irish Gaelic |
| Brogan | Descendant of Brogán | Irish Gaelic |
| Cahill | Descendant of Cathal | Irish Gaelic |
| Carney | Descendant of Cearnach | Irish Gaelic |
| Clancy | Descendant of Flannchadh | Irish Gaelic |
| Conroy | Descendant of Conraoi | Irish Gaelic |
| Corcoran | Descendant of Corcrán | Irish Gaelic |
| Costello | From Mac Oisdealbhaigh | Anglo-Norman Irish |
| Crowley | Descendant of Cruadhlaoich | Irish Gaelic |
| Doran | Descendant of Deoradhán | Irish Gaelic |
| Durkin | Descendant of Durcán | Irish Gaelic |
| Farrell | Descendant of Fearghal | Irish Gaelic |
| Geary | Descendant of Gearadh | Irish Gaelic |
| Kearney | Descendant of Cearnach | Irish Gaelic |
| Leahy | Descendant of Laochdha | Irish Gaelic |
| Mannion | Descendant of Mainchín | Irish Gaelic |
| McCullough | Son of Cullach | Irish Gaelic |
How to Choose the Right Irish Last Name
Choosing an Irish surname becomes easier when you decide what you actually need it for. For genealogy, prioritize documented family connections over a surname’s popularity or modern meaning. For fiction, consider pronunciation, historical setting, and the personality of the character.
If you are looking for a traditional Gaelic feel, surnames beginning with O’ or Mac can immediately suggest Irish naming heritage. For something more familiar internationally, names such as Murphy, Ryan, Kelly, or Byrne may feel natural.
Also check spelling carefully. Irish surnames have often changed through Anglicization, migration, and family preference. Two similar-looking names may have different histories, while one ancestral name may appear in several modern spellings.
| Name | Meaning | Origin |
| McElroy | Son of Ruaidhrí | Irish Gaelic |
| McGarry | Son of Garbhach | Irish Gaelic |
| McGinn | Son of Ginn | Irish Gaelic |
| McGuire | Son of Odhar | Irish Gaelic |
| McHale | Son of Eachthigheirn | Irish Gaelic |
| McKee | Son of Aodh | Irish Gaelic |
| McNulty | Son of Nultagh | Irish Gaelic |
| McQuaid | Son of Uaid | Irish Gaelic |
| McSweeney | Son of Suibhne | Irish Gaelic |
| McTeague | Son of Tadhg | Irish Gaelic |
| O’Beirne | Descendant of Beirn | Irish Gaelic |
| O’Callaghan | Descendant of Ceallachán | Irish Gaelic |
| O’Connell | Descendant of Conall | Irish Gaelic |
| O’Fadden | Descendant of Páidín | Irish Gaelic |
| O’Gara | Descendant of Odhar | Irish Gaelic |
| O’Halloran | Descendant of Allmhurán | Irish Gaelic |
| O’Kearney | Descendant of Cearnach | Irish Gaelic |
| O’Lonergan | Descendant of Longargán | Irish Gaelic |
| O’Quigley | Descendant of Coigligh | Irish Gaelic |
| O’Rafferty | Descendant of Raghartach | Irish Gaelic |
Final Thoughts
Irish last names are more than labels passed from one generation to another. They can preserve pieces of language, geography, occupation, ancestry, and family history. From the familiar Murphy, Kelly, and Ryan to distinctive Gaelic forms such as O’Shaughnessy, MacNamara, and O’Doherty, Irish surnames reveal the many influences that shaped Ireland’s naming traditions.
One important thing to remember is that surname meanings are not always literal descriptions of the people who carry them today. A name meaning “son of,” “descendant of,” or “red-haired” generally refers to an earlier ancestor. Likewise, a surname with Norman, English, or Scottish roots can still have a long and meaningful history in Ireland.
If you are researching your own family, use a surname as your starting point rather than proof of ancestry. Compare it with birth records, marriage documents, census information, parish registers, immigration records, and other reliable sources.
For writers and character creators, Irish surnames offer another advantage: their different sounds and histories can help establish a character’s setting and background naturally.
Ultimately, the best Irish last name depends on your purpose. Whether you want a traditional Gaelic surname, a rare family name, a historical option, or a memorable fictional surname, Ireland’s rich naming heritage provides plenty of possibilities.
What are the most common Irish last names?
Some widely recognized Irish surnames include Murphy, Kelly, O’Brien, Ryan, O’Connor, O’Neill, Walsh, Byrne, Doyle, and McCarthy. Their popularity varies by region and by the country where Irish descendants now live. A surname’s modern frequency does not necessarily indicate how old it is or how important it was historically.
What does the O mean in Irish last names?
The O in surnames such as O’Brien and O’Connor comes from the Gaelic Ó, traditionally meaning “descendant of.” It originally connected a person with a named male ancestor. The apostrophe became common in English-language spellings, although historical records can show different versions of the same surname.
What does Mc or Mac mean in Irish surnames?
Mac traditionally means “son of” in Gaelic naming traditions. It appears in surnames such as MacCarthy and MacNamara. The shortened form Mc is also common. However, spelling differences do not by themselves establish that two families share the same ancestral branch.
Are all Irish last names originally Gaelic?
No. Irish surnames come from several historical sources. Many have Gaelic origins, but others developed from Norman, English, Welsh, and other influences. Some families who arrived in Ireland from outside Gaelic society eventually became strongly associated with Irish culture and history, so the origin of a surname does not always tell the entire story of a family’s identity.