150+ Irish Last Names & Their Hidden Stories

Ever wonder about the stories behind Irish last names? These surnames are more than just identifiers; they’re linguistic windows into Ireland’s rich history, culture, and ancestry. Whether you have an Irish surname in your family tree or are simply curious about heritage, exploring these last names reveals fascinating insights about Ireland.

In this post, we’ll walk through the origins of Irish surnames, their meanings, and provide examples of some of the most popular and intriguing names. By the end, you’ll have a richer understanding of the legacy carried in these names and what they reveal about Irish heritage.

The Origins of Irish Last Names

Irish last names, or surnames, emerged around the 10th century, making them some of the oldest in European history. They often reflect an individual’s ancestry, location, or characteristics.

Patronymic Naming Tradition

The majority of Irish surnames follow a patronymic system, where names indicate lineage. The prefixes “Mac” (son of) and “Ó” (descendant of) are common markers of heritage. For example:

• MacCarthy means “son of Carthach.”
• Ó Conor translates to “descendant of Conor.”

These prefixes, which remain staples in Irish names, not only highlight family ties but also connect individuals to historical clans and lineages.

Influence of Gaelic and Norman Cultures

While most surnames have Gaelic origins, some Irish last names were influenced by Norman invaders and settlers in the 12th century. For example:

• FitzGerald derives from the Norman “Fitz,” meaning “son of,” combined with Gerald.
• Burke evolved from the town of de Burgh in Normandy.

These surnames reflect both indigenous Irish identity and the cultural exchange resulting from Ireland’s history of invasions and migrations.

Descriptive Qualities

Some Irish last names are inspired by an ancestor’s physical traits or personality. For example:

• Dubh (black) in Ó Dubhghaill refers to someone with dark features.
• Ruaidh (red) in Mac Ruaidhri denotes someone with red hair.

These names paint a vivid picture of ancestral characteristics.

Popular and Iconic Irish Last Names

Here’s a closer look at some of the most well-known Irish surnames and their meanings.

1. Murphy (Ó Murchadha)

Meaning: Descendant of Murchadh (“sea warrior”)

Murphy, the most common Irish surname, is found worldwide due to extensive Irish emigration during the 19th and 20th centuries. It signifies strength and resilience, qualities tied to its maritime origins.

2. Kelly (Ó Ceallaigh)

Meaning: Descendant of Ceallach (“bright-headed” or “warrior”)

Kelly has a proud and widespread Irish heritage. It often associates with leaders and warriors in early Gaelic clans.

3. O’Brien (Ó Briain)

Meaning: Descendant of Brian

This name originates from Brian Boru, the legendary High King of Ireland. It suggests nobility, as Brian Boru led significant efforts to unite Ireland in the 10th century.

4. Walsh (Breathnach)

Meaning: “Welshman”

Walsh refers to foreigners who came to Ireland, particularly the Britons who settled during and after the Norman invasion. It reflects Ireland’s historical ties with neighboring regions.

5. Sullivan (Ó Súilleabháin)

Meaning: Descendant of Súileabhán (“hawk-eyed”)

Sullivan is a name tied to sharpness and vision. Historically, it was a fierce family name from the Munster region in southwest Ireland.

6. MacDonald (Mac Dhomhnaill)

Meaning: Son of Dhomhnall (“ruler of the world”)

MacDonald has roots in both Ireland and Scotland, highlighting the interconnected Celtic heritage. The name signifies leadership and dominance.

7. Byrne (Ó Broin)

Meaning: Descendant of Bran (“raven”)

Associated with County Kildare, the name Byrne symbolized protection and intelligence, as ravens were considered sacred in Celtic mythology.

List of Irish Last Names and Meanings

• Donnelly – Brown valor.
• Delaney – Black and defiance.
• McNamara – From “Ó hAinmhire,” meaning “descendant of the noble.”
• Cosgrave – Son of Coscrach.
• Desmond – Topographical surname from Deasmhumhain
• Dowd – From “Ó Dubhda,” meaning “descendant of the dark one.”
• MacDermott – Son of Diarmaid (free from envy)[general knowledge]
• Cunningham – Chief or leader.
• MacMahon – Son of the bear.
• Healy – Derived from the Irish “Ó hÉilidhe,” meaning “descendant of Éilidh.”
• Muldoon – Descendant of the disciple of St. Dúin.
• McKeown – Son of Eoghan (young warrior) [general knowledge].
• Doherty – From “Ó Dochartach,” meaning “descendant of the harmed one.”
• Tiernan – Master.
• O’Flynn – Descendant of Flann, meaning “red” or “ruddy.”
• Flanagan – Red or ruddy.
• Carroll – Descendant of Cearbhaill, meaning “man of the strong hand.”
• Rochford – From the Irish “Rathbhuaidh,” meaning “place of victory.”
• Nolan – From “Ó Nualláin,” meaning “descendant of Nuallán.”
• Cameron – Derived from “cam,” meaning “crooked nose.”
• Heany – Horseman.
• Foley – From “Ó Foghlú,” meaning “descendant of the man of wealth.”
• Murray – From “Ó Muireadhaigh,” meaning “descendant of Muireadach.”
• Gannon – From “Ó Gannáin,” meaning “descendant of the fair.”
• Ennis – Island.

• Kearney – Victorious.
• Hogan – From “Ó hÓgáin,” meaning “descendant of the young.”
• Kennedy – Descendant of Cinnéidigh, meaning “helmeted head.”
• Gorman – Dark blue or noble.
• Glynn – From “Ó Glinne,” meaning “descendant of the valley.”
• O’Donnell – Descendant of Domhnall (world ruler)[general knowledge]
• O’Reilly – Descendant of Raghailleach (sociable)[general knowledge]
• Tracy – Fighter.
• O’Malley – Descendant of Máille, meaning “chief” or “leader.”
• Cullen – Derived from the holly plant.
• McDonnell – From “Ó Domhnaill,” meaning “descendant of Domhnall.”
• Crean – Descendant of Croidheagan.
• Crowley – Derived from “Ó Crualaoich,” meaning “descendant of the cruel.”
• McFadden – Derived from “Ó Fadhain,” meaning “descendant of the fortunate.”
• O’Leary – Descendant of Léimhrí, meaning “descendant of the gifted.”
• Donnell – Son of Domhnall, meaning king of the world.
• McKeogh – Son of Eochaidh.
• Gallagher – Stranger or helper.
• O’Donnell – Descendant of Donnchadh, meaning “brown chief.”
• Flynn – Son of the red-headed one
• Sheehan – From “Ó Síocháin,” meaning “descendant of peace.”
• Flannery – Red valor.
• Collins – Darling.
• MacLaughlin – Son of the hero[general knowledge]
• Hegarty – From Ó hÉigeartuigh.
• Shea – (Meaning not specified in sources but common Irish surname)
• Graham – From the Gaelic “greum,” meaning “gravelly homestead.”
• Clarke – Occupation-based, meaning “clerk” or “scribe.”
• Hayes – Fire.
• Smith – Occupation-based, meaning “blacksmith.”
• Curran – Small spear.
• Tully – From “Ó Tuatha,” meaning “descendant of the people.”
• McAllister – From “Mac Alasdair,” meaning “son of Alasdair.”
• Daugherty – Obstructive or dangerous.
• Boland – From “Ó Beolláin,” meaning “descendant of the bald one.”
• Duffy – Descendant of Dubthach, meaning dark or black
• Molloy – Proud chieftain.
• MacNamara – Son of the hound of the sea[general knowledge]
• O’Hara – Descendant of the northern Gaelic “Ó hEadhra,” meaning “descendant of the handsome one.”
• Colgan – Sword.
• Reddy – From “Ó Ríada,” meaning “descendant of the king.”
• Durnin – Little fist, associated with warriors.
• McMahon – Son of the bear.
• O’Dwyer – Descendant of Duibh, meaning “descendant of the dark one.”
• Regan – The king’s child.
• Campbell – Crooked mouth, originally Scottish but common in Ireland
• O’Houlihan – Proud.
• Cunningham – From “Ó Cuinneamhain,” meaning “descendant of the warrior.”
• Cassidy – (Meaning not specified in sources but common Irish surname)
• Donovan – Descendant of the dark brown-haired chieftain
• Shannon – From the River Shannon, meaning “old.”
• Smyth – Variant of Smith, meaning “blacksmith.”
• Patterson – Son of Patrick, meaning “son of the noble.”
• Mulligan – Grandson of the bald man.
• Kinsella – From “Ó Cinnseala,” meaning “descendant of Cinnsealach.”
• Hennessy – From Ó hAonghusa.
• Devine – From “Ó Deimhín,” meaning “descendant of the divine.”
• Carty – From “Ó Ciartha,” meaning “descendant of the dark.”
• Dunn – Dark or brown.
• Fitzpatrick – Devotee of St Patrick
• Reilly – Descendant of Raghailleach, meaning “courageous.”
• Dunne – Brown or dark.
• Lynch – Derived from the Irish “Loingseach,” meaning “mariner.”
• Mangan – From “Ó Mongáin,” meaning “descendant of Mongán.”
• Sweeney – From “Ó Suibhne,” meaning “well-born.”
• O’Connell – Descendant of Conall, meaning “strong wolf.”
• Mullen – Derived from “Ó Maolmhuire,” meaning “descendant of the servant of Mary.”
• Brennan – Descendant of Braonán, meaning “sorrow” or “descendant of Braonán.”
• Browne – From the Anglo-Saxon, meaning “brown-haired.”
• MacDonagh – Son of Donnchadh (brown warrior)[general knowledge]
• Higgins – From the Irish “Ó hUiginn,” meaning “descendant of Hugh.”
• Connor – Wolf or hound dog.
• O’Neill – Descendant of Niall.
• Maguire – From “Ó Mag Uidhir,” meaning “descendant of Uidhir.”
• O’Driscoll – Bearer of news.
• Daly – From “Ó Dálaigh,” meaning “descendant of the wise.”
• O’Farrell – Descendant of Fearghal (man of valor)[general knowledge]
• Egan – Little bright-eyed one.
• Larkin – From “Ó Lorcáin,” meaning “descendant of Lorcán.”
• O’Carroll – Disputed.
• Barrett – Derived from “Ó Barrait,” meaning “descendant of the leader.”
• McGee – From “Ó hUadha,” meaning “descendant of the good one.”
• Vaughan – From the Welsh, meaning “small” or “little.”
• Davin – Stag, fawn, or ox.
• O’Rourke – Descendant of Ruarc, meaning “famous ruler.”
• Dunne – From the Gaelic “Ó Doinn,” meaning “descendant of the dark one.”
• Bell – Bell ringer or bell maker.
• Boylan – Descendant of Baoigheallán
• O’Callaghan – Descendant of Calaghan, meaning “descendant of the warrior.”
• Hughes – From the Irish “Ó hAodha,” meaning “descendant of Aodh.”
• O’Shea – Descendant of Séaghdha (hawk-like)[general knowledge]
• Doyle – Descendant of Dubhghall, meaning dark stranger
• Kavanagh – Descendant of Caomhánach, meaning “handsome.”
• Branigan – Derived from “Ó Branagáin,” meaning “descendant of Bran.”
• Murray – From “Ó Muireadhaigh,” meaning “descendant of Muireadach.”
• Farrell – Derived from “Ó Fearghail,” meaning “descendant of Fearghal.”
• Kenny – Fiery love or fire sprung.
• Cooper – Occupation-based, meaning “barrel maker.”
• Keogh – From “Ó Céoch,” meaning “descendant of the gentle.”
• Tobin – From “Ó Tobin,” meaning “descendant of the saintly.”
• Whelan – Wolf.
• Ward – Son of the bard (storyteller).
• Keating – From the Irish Céitinn.
• Scully – Descendant of Scolaidhe.
• Cormack – From “Ó Cormac,” meaning “son of the charioteer.”
• Toner – From the Gaelic “Ó Tóinín,” meaning “descendant of Tóinín.”
• Boyle – From “Ó Baoighill,” meaning “descendant of Baoighill.”
• Harte – From “Ó hEarchadha,” meaning “descendant of Earchadh.”
• O’Connor – Descendant of Conchobhar, King of Ulster
• Fitzgerald – Son of Gerald, meaning “rule of the spear.”
• Casey – From “Ó Cathasaigh,” meaning “brave” or “vigilant.”
• Donohoe – Brown haired or battle.
• Geoghegan – Horse.
• Keane – From the Irish “Ó Cian,” meaning “descendant of Cian.”
• O’Grady – Descendant of Gráda (noble)[general knowledge].
• Ryan – Descendant of Rían, meaning “little king” or “illustrious.”
• McManus – Son of Magnus.
• Dempsey – Proud.
• Burns – From the Scottish “burn,” meaning “stream” or “brook.”
• Donnghal – Brown valour.
• Fannon – Descendant of Fionn, meaning fair or white
• Hewitt – From “Hew,” meaning “son of Hugh.”
• Madden – From “Ó Madadháin,” meaning “descendant of Madadhán.”
• Phelan – Derived from “Ó Faoláin,” meaning “descendant of Faolán.”
• Dillon – Like a lion or loyal like a lion.
• O’Doherty – Descendant of Doherty, meaning “descendant of the oak.”
• Sexton – Derived from the Anglo-French “sexton,” meaning “church servant.”
• Keegan – Derived from “Ó Céigeán,” meaning “descendant of the fiery one.”
• Coughlan – Son of the one with the cloak.
• McCarthy – Descendant of Carthach, meaning “loving” or “devoted.”
• McLaughlin – Derived from “Ó Lochlainn,” meaning “descendant of the Norsemen.”
• Quinn – From the Irish “Ó Cuinn,” meaning “descendant of Conn.”
• Barry – Spear thrower.
• O’Flaherty – Descendant of Flaithbertach (bright ruler)[general knowledge]
• Brady – Broad or spirited.
• O’Keeffe – Descendant of Ceife, meaning “descendant of the beautiful.”
• McGovern – Derived from “Ó hEaghra,” meaning “descendant of the noble.”
• Fitzsimmons – From “son of Simon,” meaning “hearing.”

The Influence of Anglicization

During English rule in Ireland, many Gaelic surnames were anglicized, altering their original meanings and spellings. For example:

• Ó Ceallaigh became Kelly.
• Ó hUiginn became Higgins.
• Mac Giolla Íosa became MacAleese.

This shift often simplified names for English pronunciation but diluted their Gaelic significance. Efforts today are underway to revive and celebrate the original Irish spellings and meanings.

The Legacy in Modern Times

Irish last names have crossed borders, carried by millions of Irish emigrants worldwide. From cities like Boston to Sydney, Irish surnames serve as cultural ambassadors, a reminder of Ireland’s resilience and global presence.

These names also connect individuals to stories of survival, hope, and pride. For many descendants of Irish immigrants, their surnames offer a direct link to an ancestral homeland, sparking journeys of self-discovery and reconnection.

How to Explore Your Irish Surname

Curious about your own Irish heritage? Start with these steps:

1. Research Your Family Tree

Use genealogy websites like Ancestry or IrishGenealogy.ie to trace your lineage.

2. Understand the Original Meaning

Explore the etymology of your surname. Irish name dictionaries and history books are great starting points.

3. Visit Your Ancestral Homeland

Many Irish surnames are tied to specific regions in Ireland. Visiting these places can offer deeper insights.

If you’re seeking professional help to explore your Irish roots, numerous cultural and genealogical organizations specialize in connecting individuals to their ancestry.

Evolution of Irish Surnames

Early Origins and Gaelic Roots
Irish surnames began to develop around the 900s, earlier than in most of Europe. Initially, they were based on a system of clan or sept names, identifying groups descended from a common ancestor and often tied to a specific territory. The earliest surnames, such as Ó Cléirigh (O’Clery), used the prefixes “Ó” (Ua, meaning “descendant of”) or “Mac” (meaning “son of”), followed by the personal name of a notable ancestor. For example, O’Neill means “descendant of Niall,” and MacCarthy means “son of Cárthach”.

Hereditary Surnames
By the 11th century, these patronymic and clan-based surnames became hereditary, passing unchanged from one generation to the next. This was a unique development in Ireland, as most European countries adopted hereditary surnames much later.

Norman Influence
From the 12th century, Anglo-Norman families arrived, bringing new surnames such as Burke (from de Burgh) and FitzGerald (“Fitz” meaning “son of” in Norman French). Over time, these Norman names were adapted into Irish forms and later anglicised alongside native surnames.

Anglicisation and Name Changes
Between the 16th and 19th centuries, Irish surnames underwent significant anglicisation, often under English rule and administrative pressures. This process included:

• Phonetic transcription: English clerks wrote Irish names as they sounded in English, leading to multiple spellings and forms for the same original name.

• Translation: Some surnames were translated for meaning or resemblance, such as Ó Foghlú (“robber”) becoming Foley, or Mac Conraoi and others becoming “King” due to the Irish word “rí” (king) in the name.

• Transposition: In some cases, clerks replaced Irish surnames with unrelated English names that sounded vaguely similar, further obscuring original meanings.

The prefixes “O’” and “Mac” were often dropped or ignored during this period, especially under laws and social pressure to conform to English norms. For example, O’Sullivan was often recorded simply as Sullivan.

Modern Revival
From the late 19th century onward, there was a resurgence in reclaiming the original Gaelic forms of surnames, with many families readopting the “O’” and “Mac” prefixes. By the early 21st century, the majority of families with these names had restored their original forms.

Summary Table: Key Stages in Irish Surname Evolution

Irish surnames today reflect this layered history, with many names showing traces of their Gaelic, Norman, and English influences.

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