Irish Last Names

Browse hundreds of Irish last names with their original Gaelic forms and meanings, from Murphy and Kelly to rarer names tied to a single county. Use the A to Z filter to explore, or search for a family name you already know.

300 real surnames with meanings, A to Z.

A

Ahern

From Ó hEachthighearna, descendant of the horse lord
Aylward

Anglo-Norman, from Old English Aethelweard, noble guardian

B

Bannon

From Ó Banáin, descendant of Banán, little white one
Barry

From de Barra, Norman family, or Ó Beargha, spear-like
Behan

From Ó Beacháin, descendant of Beachán, little bee
Boland

From Ó Beolláin, descendant of Beollán, a Norse name
Bolger

From Ó Bolguidhir, yellow belly, or a leather worker
Bourke

Variant of Burke, from Norman de Burgh
Boyle

From Ó Baoighill, possibly meaning pledge or vow
Brady

From Ó Brádaigh, descendant of Brádach, spirited
Brannigan

From Ó Branagáin, descendant of Branagán, little raven
Brennan

From Ó Braonáin, descendant of Braonán, sorrow or moisture
Breslin

From Ó Breisleáin, descendant of Breisleán, possibly strife
Brophy

From Ó Bróithe, descendant of Bróth, of uncertain meaning
Brosnan

From Ó Brosnacháin, from the Brosna river in Kerry
Browne

Norman origin, nickname for brown hair, a Tribe of Galway
Buckley

From Ó Buachalla, descendant of the boy or herdsman
Burke

From Norman de Burgh, of the fortress
Byrne

From Ó Broin, descendant of Bran, meaning raven

C

Cahill

From Ó Cathail, descendant of Cathal, battle ruler
Callaghan

Anglicised Ó Ceallacháin, little bright headed one
Callinan

From Ó Callanáin, descendant of Callanán
Canavan

From Ó Ceanndubháin, descendant of the black headed one
Carey

From Ó Ciardha, descendant of Ciardha, dark one
Carroll

From Ó Cearbhaill, descendant of Cearbhall, fierce in battle
Casey

From Ó Cathasaigh, descendant of Cathasach, vigilant
Cassidy

From Ó Caiside, descendant of Caiside, possibly curly haired
Cawley

From Mac Amhalghaidh, son of Amhalghadh, an ancient name
Clancy

From Mac Fhlannchaidh, son of Flannchadh, red warrior
Cleary

From Ó Cléirigh, descendant of the clerk or cleric
Coffey

From Ó Cobhthaigh, descendant of Cobhthach, victorious
Colgan

From Ó Colgan, descendant of Colga, sword
Collins

From Ó Coileáin, descendant of Coileán, young hound
Comerford

Norman origin, from Comberford in Staffordshire
Conneely

From Mac Conghaile, son of Conghal, fierce as a hound
Connolly

From Ó Conghalaigh, descendant of Conghalach, valiant
Connors

From Ó Conchobhair, descendant of Conchobhar, hound lover
Conroy

From Ó Conaire, descendant of Conaire, hound keeper
Considine

From Mac Consaidín, son of Constantine
Conway

From Mac Conmidhe or Ó Conbhuidhe, yellow hound
Corcoran

From Ó Corcráin, descendant of Corcrán, purple or ruddy
Corrigan

From Ó Corragáin, descendant of Corragán, spear
Costello

From Mac Oisdealbhaigh, son of Oisdealbh, deer like
Coughlan

From Ó Cochláin, descendant of Cochlán, cloaked one
Coyle

From Mac Giolla Chomhghaill, servant of Saint Comgall
Cronin

From Ó Cróinín, descendant of Cróinín, little dark one
Crowe

From Mac Conchradha, son of Conchradha, hound of Cradh
Crowley

From Ó Cruadhlaoich, descendant of the hardy warrior
Cuddihy

From Ó Cuidighthigh, descendant of the helper
Cullen

From Ó Cuilinn, descendant of Cuileann, holly
Cummins

From Ó Coimín, descendant of Coimín, bent one
Cunnane

From Ó Cuineáin, descendant of Cuineán, possibly little hound
Curran

From Ó Corráin, descendant of Corrán, spear or sickle
Curtin

From Mac Cruitín, son of Cruitín, the hunchback
Cusack

Norman origin, from Cussac in Guienne

D

Daly

From Ó Dálaigh, descendant of Dálach, assembly
Darcy

Norman d'Arcy, or Ó Dorchaidhe, the dark one
Deasy

From Déiseach, a person from the Decies of Waterford
Delaney

From Ó Dubhshláine, dark one of the River Slaney
Dempsey

From Ó Díomasaigh, descendant of Díomasach, proud
Devane

From Ó Dubháin, descendant of Dubhán, little dark one
Devaney

From Ó Duibheannaigh, descendant of the black Eannach
Devine

From Ó Daimhín, descendant of Daimhín, little ox
Devlin

From Ó Doibhilin, possibly meaning fierce or unlucky
Dillon

From Norman de Leon, or Ó Duilleáin, descendant of Duilleán
Doherty

From Ó Dochartaigh, descendant of the obstructive one
Dolan

From Ó Dubhláin, descendant of Dubhlán, dark defiance
Donnelly

From Ó Donnghaile, descendant of Donnghal, brown valour
Donohoe

From Ó Donnchadha, descendant of Donnchadh, brown warrior
Donovan

From Ó Donnabháin, descendant of Donndubhán, dark brown
Doran

From Ó Deoradháin, descendant of the exile or pilgrim
Dowd

From Ó Dubhda, descendant of Dubhda, the dark one
Dowling

From Ó Dúnlaing, descendant of Dúnlang, a Leinster name
Downey

From Ó Dúnadhaigh, descendant of the fortress holder
Doyle

From Ó Dubhghaill, descendant of the dark foreigner
Drennan

From Ó Draighneáin, descendant of Draighneán, blackthorn
Duffy

From Ó Dubhthaigh, descendant of Dubhthach, dark one
Duggan

From Ó Dubhagáin, descendant of Dubhagán, little dark one
Dunne

From Ó Duinn, descendant of Donn, brown or chieftain
Dunphy

From Ó Donnchadha, descendant of Donnchadh, brown warrior
Durkan

From Mac Dhuarcáin, son of Duarcán, the gloomy one
Dwyer

From Ó Duibhir, descendant of Duibhir, dark tawny

E

Egan

From Mac Aodhagáin, son of little Aodh, fire
Ennis

From Ó hAonghuis, descendant of Aonghus, one choice

F

Fahy

From Ó Fathaigh, descendant of Fathadh, foundation
Fallon

From Ó Fallamhain, descendant of Fallamhan, leader
Farrell

From Ó Fearghail, descendant of Fearghal, man of valour
Feeney

From Ó Fiannaidhe, descendant of the soldier or warrior
Fenlon

From Ó Fionnalláin, descendant of Fionnallán, fair one
Finn

From Ó Finn, descendant of Fionn, fair or white
Finnegan

From Ó Fionnagáin, descendant of Fionnagán, fair one
Fitzgerald

Norman patronymic, son of Gerald, spear rule
Fitzpatrick

Anglicised Mac Giolla Phádraig, son of Patrick's devotee
Fitzsimons

Norman patronymic, son of Simon, he has heard
Flaherty

From Ó Flaithbheartaigh, descendant of the bright ruler
Flanagan

From Ó Flannagáin, descendant of Flannagán, red or ruddy
Flood

From Ó Maoltuile, or English, dweller by a channel
Flynn

From Ó Floinn, descendant of Flann, red or ruddy
Fogarty

From Ó Fógartaigh, descendant of Fógartach, banished
Foley

From Ó Foghladha, descendant of the plunderer
Furlong

Norman origin, from a measure of land, Wexford

G

Gallagher

From Ó Gallchobhair, descendant of Gallchobhar, foreign help
Garvey

From Ó Gairbhith, descendant of Gairbhith, rough peace
Gavin

From Ó Gábháin, descendant of Gábhán, want or need
Geraghty

From Mag Oireachtaigh, son of the assembly member
Gilligan

From Mac Giollagáin, son of the little devotee
Gilmartin

From Mac Giolla Mhártain, son of Martin's devotee
Gleeson

From Ó Glasáin, descendant of Glasán, the grey green one
Gorman

From Ó Gormáin, descendant of Gormán, little blue one
Griffin

From Ó Gríobhtha, descendant of Gríobhtha, griffin-like
Grogan

From Ó Gruagáin, descendant of Gruagán, possibly from gruag, hair
Guilfoyle

From Mac Giolla Phóil, son of Saint Paul's devotee

H

Hackett

Norman origin, from a diminutive of Hake, hook
Hanley

From Ó hÁinle, descendant of Áinle, the beautiful one
Hanlon

From Ó hAnluain, descendant of Anluan, great champion
Hannon

From Ó hAnnáin, descendant of Annán, possibly delay
Harkin

From Ó hEarcáin, descendant of Earcán, little red one
Hartigan

From Ó hArtagáin, descendant of Artagán, little bear
Hayes

From Ó hAodha, descendant of Aodh, meaning fire
Healy

From Ó hÉilidhe, claimant, or Ó hÉalaighthe, ingenious
Heffernan

From Ó hIfearnáin, descendant of Ifearnán, little demon
Hennessy

From Ó hAonghusa, descendant of Aonghus, one choice
Hickey

From Ó hÍcidhe, descendant of the healer
Higgins

From Ó hUiginn, descendant of Uiginn, possibly Viking
Hoban

From Ó hÚbáin, descendant of Úbán, possibly little cub
Hoey

From Ó hEochaidh, descendant of Eochaidh, horseman
Hogan

From Ó hÓgáin, descendant of Ógán, young man
Horgan

From Ó hArgáin, descendant of Argán, possibly warrior
Houlihan

From Ó hUallacháin, descendant of the proud little one
Hurley

From Ó hUrthuile, descendant of the sea tide

J

Joyce

Norman origin, from Breton personal name Iodoc, lord
Judge

Translation of Mac an Bhreitheamhan, son of the judge

K

Kane

From Ó Catháin, descendant of Cathán, little battle
Kavanagh

From Caomhánach, follower of Saint Caomhán, gentle
Keane

From Ó Céin, descendant of Cian, ancient or enduring
Kearney

From Ó Cearnaigh, descendant of Cearnach, victorious
Kearns

From Ó Céirín, descendant of Céirín, little dark one
Keating

Norman origin, from Cétyn, or Welsh Cethin, dusky
Kehoe

From Mac Eochaidh, son of Eochaidh, horseman
Kelleher

From Ó Céileachair, descendant of Céileachar, companion loving
Kelly

From Ó Ceallaigh, descendant of Ceallach, possibly bright headed or strife
Kennedy

From Ó Cinnéide, descendant of Cinnéidigh, helmeted head
Kenny

From Ó Cionaoith, descendant of Cionaodh, born of fire
Keogh

From Mac Eochaidh, son of Eochaidh, horseman
Keohane

From Ó hEocháin, descendant of Eochán, little horseman
Kerrigan

From Ó Ciaragáin, descendant of Ciaragán, little dark one
Kiely

From Ó Cadhla, descendant of Cadhla, graceful
Kilbride

From Mac Giolla Bhrighde, son of Saint Brigid's servant
Kilkenny

From Mac Giolla Chainnigh, son of Saint Canice's servant
Kinsella

From Cinnsealach, a Leinster sept name, proud
Kirwan

From Ó Ciardhubháin, descendant of the black dark one

L

Lacey

Norman de Lacy, from Lassy in Calvados
Lally

From Ó Maolalaidh, of uncertain meaning
Larkin

From Ó Lorcáin, descendant of Lorcán, fierce
Lavelle

From Ó Maolfhábhail, descendant of the chief of travel
Lawlor

From Ó Leathlobhair, descendant of the half leper
Leahy

From Ó Laochdha, descendant of the heroic one
Lenihan

From Ó Leannacháin, descendant of the cloaked one
Lonergan

From Ó Longargáin, possibly meaning strong and fierce
Looney

From Ó Luanaigh, descendant of Luanach, warrior
Loughran

From Ó Luachráin, descendant of Luachrán, rushes
Lucey

From Ó Luasaigh, descendant of Luasach, of uncertain meaning
Lydon

From Ó Loideáin, descendant of Loideán, possibly a snare
Lynch

From Ó Loingsigh, descendant of the seafarer
Lyons

From Ó Liatháin, descendant of Liathán, grey one

M

Macken

From Ó Macáin, descendant of Macán, little son
Madden

From Ó Madáin, descendant of Madán, little dog
Magee

From Mac Aodha, son of Aodh, meaning fire
Maguire

From Mag Uidhir, son of Odhar, dun coloured
Maher

From Ó Meachair, descendant of Meachar, hospitable
Mahon

From Ó Mathghamhna, descendant of the bear
Malone

From Ó Maoileoin, descendant of Saint John's devotee
Maloney

From Ó Maoldhomhnaigh, descendant of the church servant
Mangan

From Ó Mongáin, descendant of Mongán, the maned one
Mannion

From Ó Mainnín, descendant of Mainnín, of uncertain meaning
Markey

From Ó Marcaigh, descendant of the horseman
McAuley

From Mac Amhalghaidh, son of Amhalghadh, ancient name
McCabe

From Mac Cába, son of Cába, a cap or hood
McCann

From Mac Cana, son of Cana, wolf cub
McCarthy

From Mac Cárthaigh, son of Cárthach, loving
McCormack

From Mac Cormaic, son of Cormac, chariot lad
McDermott

From Mac Diarmada, son of Diarmaid, free man
McDonagh

From Mac Donnchadha, son of Donnchadh, brown warrior
McDonnell

From Mac Domhnaill, son of Domhnall, world ruler
McEvoy

From Mac Fhíodhbhuidhe, son of the woodsman
McGee

From Mac Aodha, son of Aodh, fire
McGettigan

From Mac Eiteagáin, son of Eiteagán, little wing
McGovern

From Mag Shamhradháin, son of Samhradhán, summer
McGowan

From Mac an Ghabhann, son of the smith
McGrath

From Mac Craith, son of Craith, grace or prosperity
McGuinness

From Mag Aonghusa, son of Aonghus, one choice
McHugh

From Mac Aodha, son of Aodh, meaning fire
McInerney

From Mac an Airchinnigh, son of the church steward
McKenna

From Mac Cionaoith, son of Cionaodh, born of fire
McKeown

From Mac Eoghain, son of Eoghan, born of the yew
McLaughlin

From Mac Lochlainn, son of the Viking or Norseman
McLoughlin

From Mac Lochlainn, son of the Norseman
McMahon

From Mac Mathghamhna, son of the bear
McManus

From Mac Maghnuis, son of Magnus, great
McNally

From Mac an Fhailghigh, son of the poor man
McNamara

From Mac Conmara, son of the hound of the sea
McNulty

From Mac an Ultaigh, son of the Ulsterman
McQuaid

From Mac Uaid, son of Wat, a form of Walter
Meehan

From Ó Miadhacháin, descendant of the honourable one
Minogue

From Ó Muineóg, descendant of Muineóg, of uncertain meaning
Molloy

From Ó Maolmhuaidh, descendant of the noble chief
Monaghan

From Ó Manacháin, descendant of Manachán, little monk
Mooney

From Ó Maonaigh, descendant of Maonach, wealthy
Moran

From Ó Móráin, descendant of Mórán, great one
Moriarty

From Ó Muircheartaigh, descendant of the sea navigator
Mulcahy

From Ó Maolchathaigh, devotee of Saint Cathach
Mullan

From Ó Maoláin, descendant of Maolán, little bald one
Mulligan

From Ó Maolagáin, descendant of the little bald one
Mullins

From Ó Maoláin, descendant of the little tonsured one
Mulrooney

From Ó Maolruanaidh, devotee of Ruanadh
Mulvey

From Ó Maolmhiadhaigh, descendant of the honourable chief
Murphy

From Ó Murchadha, descendant of Murchadh, sea warrior
Murray

From Ó Muireadhaigh, descendant of Muireadhach, lord or master

N

Nagle

Norman de Angulo, from an angle or corner
Naughton

From Ó Neachtain, descendant of Neachtan, pure
Neville

Norman de Neuville, from the new settlement
Nolan

From Ó Nualláin, descendant of Nuallán, famous champion
Noonan

From Ó hIonmhaineáin, descendant of the little beloved one
Nugent

Norman origin, from Nogent in France

O

O'Brien

Descendant of Brian, high king, meaning noble
O'Callaghan

From Ó Ceallacháin, descendant of little Ceallach, bright
O'Carroll

From Ó Cearbhaill, descendant of Cearbhall, fierce in battle
O'Connell

From Ó Conaill, descendant of Conall, strong as a wolf
O'Connor

From Ó Conchobhair, descendant of Conchobhar, hound lover
O'Dea

From Ó Deaghaidh, descendant of Deaghadh, good one
O'Doherty

From Ó Dochartaigh, descendant of the hurtful one
O'Donnell

From Ó Domhnaill, descendant of Domhnall, world ruler
O'Donoghue

From Ó Donnchadha, descendant of Donnchadh, brown warrior
O'Driscoll

From Ó hEidirsceoil, descendant of the interpreter
O'Dwyer

From Ó Duibhir, descendant of Duibhir, dark tawny
O'Flynn

From Ó Floinn, descendant of Flann, ruddy
O'Gara

From Ó Gadhra, descendant of Gadhra, hound
O'Grady

From Ó Grádaigh, descendant of Grádach, noble
O'Halloran

From Ó hAllmhuráin, stranger from beyond the sea
O'Hara

From Ó hEaghra, descendant of Eaghra, a Sligo chief
O'Keeffe

From Ó Caoimh, descendant of Caomh, gentle or kind
O'Kelly

From Ó Ceallaigh, descendant of Ceallach, possibly bright headed or strife
O'Leary

From Ó Laoghaire, descendant of the calf keeper
O'Loughlin

From Ó Lochlainn, descendant of Lochlann, the Norseman
O'Mahony

From Ó Mathghamhna, descendant of the bear
O'Malley

From Ó Máille, descendant of Máille, a Mayo chieftain
O'Meara

From Ó Meadhra, descendant of Meadhair, merry
O'Neill

From Ó Néill, descendant of Niall, champion
O'Reilly

From Ó Raghailligh, descendant of Raghallach, possibly valiant
O'Riordan

From Ó Ríoghbhardáin, descendant of the royal bard
O'Rourke

From Ó Ruairc, descendant of Ruarc, a Norse name
O'Shea

From Ó Séaghdha, descendant of Séaghdha, hawk-like
O'Sullivan

From Ó Súilleabháin, from súil, eye, possibly dark eyed or one eyed
O'Toole

From Ó Tuathail, descendant of Tuathal, people mighty

P

Phelan

From Ó Faoláin, descendant of Faolán, little wolf
Plunkett

Norman origin, possibly from Plouquenet in Brittany
Power

From Norman le Poer, the poor man or pauper
Prendergast

Norman origin, from Brontegeest in Flanders
Purcell

Norman origin, from Old French pourcel, little pig

Q

Quigley

From Ó Coigligh, descendant of the untidy haired one
Quilty

From Ó Caoilte, descendant of Caoilte, slender
Quinn

From Ó Cuinn, descendant of Conn, chief or wisdom
Quirke

From Ó Cuirc, descendant of Corc, heart or crimson

R

Rabbitte

Translation of Ó Coinín, descendant of Coinín, rabbit
Rafferty

From Ó Raithbheartaigh, wielder of prosperity
Redmond

Norman origin, from Germanic Raymond, counsel protection
Regan

From Ó Riagáin, descendant of Riagán, little king
Reilly

From Ó Raghailligh, descendant of Raghallach
Riordan

From Ó Ríoghbhardáin, descendant of the royal poet
Roche

Norman origin, from de la Roche, of the rock
Ronan

From Ó Rónáin, descendant of Rónán, little seal
Rooney

From Ó Ruanaidh, descendant of Ruanaidh, champion
Ryan

From Ó Riain, descendant of Rian, little king

S

Scanlon

From Ó Scannláin, descendant of Scannlán, little contention
Scully

From Ó Scolaidhe, descendant of the scholar or student
Shanahan

From Ó Seanacháin, descendant of the wise old one
Shannon

From Ó Seanáin, descendant of Seanán, little old wise one
Sheedy

From Ó Síoda, descendant of Síoda, silk
Sheehan

From Ó Síodhacháin, descendant of the peaceful one
Sheridan

From Ó Sirideáin, descendant of Sirideán, seeker
Shine

From Ó Seighin, descendant of Seighin, a hawk
Slattery

From Ó Slatara, descendant of the strong or bold one
Stack

Anglo-Norman origin, settled in Kerry from the 13th century
Stapleton

Norman origin, from Stapleton in Yorkshire
Sullivan

From Ó Súilleabháin, from súil, eye, possibly dark eyed or one eyed
Sweeney

From Mac Suibhne, son of Suibhne, pleasant

T

Taaffe

Norman Welsh origin, from Welsh Dafydd, David
Tierney

From Ó Tighearnaigh, descendant of Tighearnach, lord
Tighe

From Ó Taidhg, descendant of Tadhg, poet
Timmins

From Ó Tiomáin, descendant of Tiomán, or English Timothy
Tobin

Norman origin, from Saint-Aubin in France
Toner

From Ó Tomhrair, descendant of Tomhrar, a Norse name
Treacy

From Ó Treasaigh, descendant of Treasach, warlike
Troy

From Ó Troighthigh, descendant of the foot soldier
Tully

From Ó Maoltuile, devotee of the will of God
Tuohy

From Ó Tuathaigh, descendant of Tuathach, ruler of a people
Twomey

From Ó Tuama, descendant of Tuaim, a burial mound

W

Walsh

From Breathnach, meaning Welshman or Briton
Ward

From Mac an Bhaird, son of the bard or poet
Whelan

From Ó Faoláin, descendant of Faolán, little wolf

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McGrath

From Mac Craith, son of Craith, grace or prosperity
Egan

From Mac Aodhagáin, son of little Aodh, fire
Hennessy

From Ó hAonghusa, descendant of Aonghus, one choice
McInerney

From Mac an Airchinnigh, son of the church steward
Gilligan

From Mac Giollagáin, son of the little devotee
McDonnell

From Mac Domhnaill, son of Domhnall, world ruler

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Irish surnames and meanings: Mac, Ó and Gaelic roots

Most Irish surnames began as Gaelic patronymics. Mac means son of and Ó means grandson or descendant of, so Mac Mathúna became MacMahon and Ó Briain became O'Brien, the descendants of the high king Brian Boru. Many of these names were fixed between the tenth and twelfth centuries, making Ireland one of the first countries in Europe to use hereditary surnames. The name after the prefix is usually an old personal name with its own meaning.

Murphy comes from Ó Murchadha, from a name meaning sea warrior. Kelly is Ó Ceallaigh, often explained as bright-headed or linked to strife. O'Sullivan is Ó Súilleabháin, possibly dark-eyed or hawk-eyed. Byrne is Ó Broin, from a name meaning raven, and O'Connor is Ó Conchobhair, lover of hounds. Walsh is different: it comes from Breathnach, meaning Welshman, and was given to Welsh and Cambro-Norman settlers who arrived after 1169.

Most common Irish surnames and rare Irish surnames

Murphy is usually the most common surname in Ireland, followed by Kelly, O'Sullivan, Walsh, Smith, O'Brien, Byrne, Ryan, O'Connor and O'Neill. Smith is a mix of English settler names and translations of the Gaelic Mac Gabhann, son of the smith. Norman families added names such as FitzGerald, Burke, Power and Butler, and after several generations many of them were described as more Irish than the Irish themselves.

Rarer names are often tied to a single county or even a single parish. Mulvihill belongs mainly to north Kerry, west Limerick and Clare, Kinsella to Wexford and Hession to Galway. Names like these can place a character precisely. Some rare names are simply unusual anglicizations: the same Gaelic name may appear as Gallagher, Gallaher or Gallogher, and a few spellings survive in only a handful of families.

How anglicization reshaped Irish last names

Under English rule, especially from the seventeenth century, Gaelic names were written down by clerks who did not speak Irish. Many families dropped the O and Mac prefixes, which is why Murphy, Kelly and Ryan so often appear without them. Some names were translated rather than transcribed, so Mac Gabhann became Smith and Ó Bradáin became Salmon. The Gaelic revival of the late nineteenth century led many families in Ireland to restore their prefixes, while emigrant branches often kept shorter forms like Sullivan.

Irish-language forms also change for women. A daughter of Ó Briain is Ní Bhriain, and a daughter of Mac Mathúna is Nic Mhathúna. A married woman may use Bean Uí Bhriain, wife of O'Brien. English spellings do not change, so in daily life most people simply use O'Brien or MacMahon. For a character, pairing an Irish-language first name like Aoife or Cian with an anglicized surname reflects how names are actually used in Ireland today.

Frequently asked questions

What are the most common Irish surnames?

Murphy, Kelly, O'Sullivan, Walsh, Smith, O'Brien, Byrne, Ryan, O'Connor and O'Neill usually rank highest. Several of these, including Murphy and Kelly, are more common without their original Ó prefix because it was dropped during the centuries of anglicization.

Where do Irish last names with Fitz come from?

Fitz comes from the Norman French fils, meaning son. It arrived with the Anglo-Norman invasion of 1169 and appears in names such as FitzGerald and FitzGibbon. FitzPatrick is an exception with Gaelic roots, a Norman-style rendering of Mac Giolla Phádraig.

What is the difference between O and Mac in Irish surnames?

Mac means son of and Ó means grandson or descendant of, so Ó usually points to a more distant founding ancestor. Both became fixed family names centuries ago, so today neither tells you anything about a specific father or grandfather.

Why do both Mc and Mac appear in the Irish surnames list?

Mc is simply an abbreviated spelling of Mac, meaning son of. The popular belief that Mac is Scottish and Mc is Irish is a myth, since both spellings are found in both countries. Clerks and families chose spellings freely, and many relatives use different forms.