Gaelic Last Names

These Gaelic last names are real Irish and Scottish family names, listed A to Z with the Gaelic form and meaning behind each one. See how Ó Briain became O'Brien and why Gilchrist and Malone point back to Christian devotion.

300 real surnames with meanings, A to Z.

A

Adamson

Son of Adam, meaning earth or man

Scottish
Ahern

From Ó hEachthighearna, descendant of the horse lord

Irish
Aitken

Scots diminutive of Adam, earth or man

Scottish
Alexander

From Greek personal name, defender of men

Scottish
Allan

From Gaelic or Breton personal name Alan, possibly little rock

Scottish
Anderson

Son of Andrew, patron saint of Scotland

Scottish
Angus

From Gaelic Aonghus, meaning one choice

Scottish
Armstrong

Border clan nickname for a strong-armed man

Scottish

B

Baird

From Gaelic bàrd, meaning poet or bard

Scottish
Barry

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

Irish
Beattie

Diminutive of Bartholomew, Border clan name

Scottish
Bell

From the bell, a house sign or bell ringer

Scottish
Black

Nickname for someone with dark hair or complexion

Scottish
Blair

Habitational name from Gaelic blàr, meaning plain or field

Scottish
Boland

From Ó Beolláin, descendant of Beollán, a Norse name

Irish
Bourke

Variant of Burke, from Norman de Burgh

Irish
Boyd

From Gaelic buidhe, meaning yellow haired, or from Bute

Scottish
Boyle

From Ó Baoighill, possibly meaning pledge or vow

Irish
Brady

From Ó Brádaigh, descendant of Brádach, spirited

Irish
Brennan

From Ó Braonáin, descendant of Braonán, sorrow or moisture

Irish
Brodie

Habitational name from Moray, possibly ditch or muddy place

Scottish
Browne

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

Irish
Bruce

Norman origin, from Brix in Normandy, royal house

Scottish
Buchan

Regional name from the district of Buchan, Aberdeenshire

Scottish
Buchanan

Habitational name from Stirlingshire, house of the canon

Scottish
Buckley

From Ó Buachalla, descendant of the boy or herdsman

Irish
Burke

From Norman de Burgh, of the fortress

Irish
Burns

Dweller by a burn or stream

Scottish
Byrne

From Ó Broin, descendant of Bran, meaning raven

Irish

C

Cahill

From Ó Cathail, descendant of Cathal, battle ruler

Irish
Cairns

Dweller by a heap of stones or cairn

Scottish
Calder

Habitational name meaning hard or violent water

Scottish
Callaghan

Anglicised Ó Ceallacháin, little bright headed one

Irish
Cameron

From Gaelic cam sròn, meaning crooked nose

Scottish
Campbell

From Gaelic cam beul, meaning crooked mouth

Scottish
Carey

From Ó Ciardha, descendant of Ciardha, dark one

Irish
Carmichael

Habitational name from Lanarkshire, fort of Michael

Scottish
Carroll

From Ó Cearbhaill, descendant of Cearbhall, fierce in battle

Irish
Casey

From Ó Cathasaigh, descendant of Cathasach, vigilant

Irish
Cassidy

From Ó Caiside, descendant of Caiside, possibly curly haired

Irish
Chalmers

Scots form of Chambers, a chamberlain

Scottish
Chisholm

Habitational name from Roxburghshire, water meadow for cheese

Scottish
Christie

Diminutive of Christian or Christopher

Scottish
Clancy

From Mac Fhlannchaidh, son of Flannchadh, red warrior

Irish
Cleary

From Ó Cléirigh, descendant of the clerk or cleric

Irish
Cochrane

Habitational name from Renfrewshire, possibly red brook

Scottish
Coffey

From Ó Cobhthaigh, descendant of Cobhthach, victorious

Irish
Collins

From Ó Coileáin, descendant of Coileán, young hound

Irish
Connolly

From Ó Conghalaigh, descendant of Conghalach, valiant

Irish
Connors

From Ó Conchobhair, descendant of Conchobhar, hound lover

Irish
Conroy

From Ó Conaire, descendant of Conaire, hound keeper

Irish
Conway

From Mac Conmidhe or Ó Conbhuidhe, yellow hound

Irish
Corcoran

From Ó Corcráin, descendant of Corcrán, purple or ruddy

Irish
Costello

From Mac Oisdealbhaigh, son of Oisdealbh, deer like

Irish
Coughlan

From Ó Cochláin, descendant of Cochlán, cloaked one

Irish
Cowan

From Gaelic Mac Eoghainn, or a mason or cave dweller

Scottish
Craig

Dweller by a crag or rocky hill

Scottish
Crawford

Habitational name from Lanarkshire, crow ford

Scottish
Crichton

Habitational name from Midlothian, border settlement

Scottish
Cronin

From Ó Cróinín, descendant of Cróinín, little dark one

Irish
Crowley

From Ó Cruadhlaoich, descendant of the hardy warrior

Irish
Cruickshank

Nickname for a bow legged man

Scottish
Cullen

From Ó Cuilinn, descendant of Cuileann, holly

Irish
Cumming

Norman origin, from Comines in Flanders

Scottish
Cummins

From Ó Coimín, descendant of Coimín, bent one

Irish
Cunningham

Habitational name from Ayrshire district of Cunninghame

Scottish
Curran

From Ó Corráin, descendant of Corrán, spear or sickle

Irish
Currie

Habitational name from Gaelic currach, wet plain

Scottish

D

Daly

From Ó Dálaigh, descendant of Dálach, assembly

Irish
Darcy

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

Irish
Davidson

Son of David, beloved, a Highland clan

Scottish
Delaney

From Ó Dubhshláine, dark one of the River Slaney

Irish
Dempsey

From Ó Díomasaigh, descendant of Díomasach, proud

Irish
Devine

From Ó Daimhín, descendant of Daimhín, little ox

Irish
Devlin

From Ó Doibhilin, possibly meaning fierce or unlucky

Irish
Dewar

Occupational name for a keeper of a saint's relic

Scottish
Dickson

Son of Dick, a pet form of Richard

Scottish
Dillon

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

Irish
Docherty

From Gaelic Ó Dochartaigh, descendant of the hurtful one

Scottish
Doherty

From Ó Dochartaigh, descendant of the obstructive one

Irish
Dolan

From Ó Dubhláin, descendant of Dubhlán, dark defiance

Irish
Donnelly

From Ó Donnghaile, descendant of Donnghal, brown valour

Irish
Donohoe

From Ó Donnchadha, descendant of Donnchadh, brown warrior

Irish
Donovan

From Ó Donnabháin, descendant of Donndubhán, dark brown

Irish
Doran

From Ó Deoradháin, descendant of the exile or pilgrim

Irish
Douglas

From Gaelic dubh glas, meaning dark stream

Scottish
Dowd

From Ó Dubhda, descendant of Dubhda, the dark one

Irish
Dowling

From Ó Dúnlaing, descendant of Dúnlang, a Leinster name

Irish
Downey

From Ó Dúnadhaigh, descendant of the fortress holder

Irish
Doyle

From Ó Dubhghaill, descendant of the dark foreigner

Irish
Drummond

Habitational name from Drymen, Stirlingshire, ridge

Scottish
Duff

From Gaelic dubh, meaning dark or black

Scottish
Duffy

From Ó Dubhthaigh, descendant of Dubhthach, dark one

Irish
Duggan

From Ó Dubhagáin, descendant of Dubhagán, little dark one

Irish
Dunbar

Habitational name from East Lothian, summit fort

Scottish
Duncan

From Gaelic Donnchadh, meaning brown warrior

Scottish
Dunlop

Habitational name from Ayrshire, muddy hill

Scottish
Dunne

From Ó Duinn, descendant of Donn, brown or chieftain

Irish
Dwyer

From Ó Duibhir, descendant of Duibhir, dark tawny

Irish

E

Egan

From Mac Aodhagáin, son of little Aodh, fire

Irish
Elliot

Border clan name, possibly from Old English Elwald

Scottish
Erskine

Habitational name from Renfrewshire, green rising ground

Scottish

F

Fallon

From Ó Fallamhain, descendant of Fallamhan, leader

Irish
Farrell

From Ó Fearghail, descendant of Fearghal, man of valour

Irish
Feeney

From Ó Fiannaidhe, descendant of the soldier or warrior

Irish
Ferguson

Son of Fergus, meaning man of vigour

Scottish
Fife

Regional name from the kingdom of Fife

Scottish
Findlay

From Gaelic Fionnlagh, meaning fair warrior

Scottish
Finn

From Ó Finn, descendant of Fionn, fair or white

Irish
Finnegan

From Ó Fionnagáin, descendant of Fionnagán, fair one

Irish
Fitzgerald

Norman patronymic, son of Gerald, spear rule

Irish
Fitzpatrick

Anglicised Mac Giolla Phádraig, son of Patrick's devotee

Irish
Flaherty

From Ó Flaithbheartaigh, descendant of the bright ruler

Irish
Flanagan

From Ó Flannagáin, descendant of Flannagán, red or ruddy

Irish
Fleming

Ethnic name for a settler from Flanders

Scottish
Flynn

From Ó Floinn, descendant of Flann, red or ruddy

Irish
Fogarty

From Ó Fógartaigh, descendant of Fógartach, banished

Irish
Foley

From Ó Foghladha, descendant of the plunderer

Irish
Forbes

Habitational name from Aberdeenshire, field or district

Scottish
Forsyth

Possibly from Gaelic Fearsithe, man of peace, or a place name

Scottish
Fraser

Norman origin, possibly from strawberry, fraise

Scottish
Fyfe

Regional name from Fife, Scots spelling

Scottish

G

Galbraith

From Gaelic gall Breathnach, foreign Briton

Scottish
Gallagher

From Ó Gallchobhair, descendant of Gallchobhar, foreign help

Irish
Garvey

From Ó Gairbhith, descendant of Gairbhith, rough peace

Irish
Gavin

From Ó Gábháin, descendant of Gábhán, want or need

Irish
Geddes

Habitational name from Nairn, or from a pike fish

Scottish
Gilchrist

From Gaelic Gille Chriosd, servant of Christ

Scottish
Gillespie

From Gaelic Gille Easbuig, servant of the bishop

Scottish
Gillies

From Gaelic Gille Iosa, servant of Jesus

Scottish
Gilmour

From Gaelic Gille Moire, servant of the Virgin Mary

Scottish
Gleeson

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

Irish
Gordon

Habitational name from Berwickshire, spacious fort

Scottish
Gorman

From Ó Gormáin, descendant of Gormán, little blue one

Irish
Graham

From Grantham in Lincolnshire, gravelly homestead

Scottish
Grant

From Norman French graund, meaning tall or large

Scottish
Griffin

From Ó Gríobhtha, descendant of Gríobhtha, griffin-like

Irish
Gunn

From Old Norse personal name Gunnr, meaning battle

Scottish
Guthrie

Habitational name from Angus, windy place

Scottish

H

Hamilton

Habitational name from Hameldune in Leicestershire

Scottish
Hanley

From Ó hÁinle, descendant of Áinle, the beautiful one

Irish
Hanlon

From Ó hAnluain, descendant of Anluan, great champion

Irish
Hay

Norman origin, from La Haye, meaning hedge

Scottish
Hayes

From Ó hAodha, descendant of Aodh, meaning fire

Irish
Healy

From Ó hÉilidhe, claimant, or Ó hÉalaighthe, ingenious

Irish
Henderson

Son of Henry, meaning home ruler

Scottish
Hendry

Scots form of Henry, home ruler

Scottish
Hennessy

From Ó hAonghusa, descendant of Aonghus, one choice

Irish
Hickey

From Ó hÍcidhe, descendant of the healer

Irish
Higgins

From Ó hUiginn, descendant of Uiginn, possibly Viking

Irish
Hogan

From Ó hÓgáin, descendant of Ógán, young man

Irish
Hogg

Occupational name for a swineherd or a young sheep

Scottish
Hume

Habitational name from Berwickshire, hill or hollow

Scottish
Hunter

Occupational name for a hunter

Scottish
Hurley

From Ó hUrthuile, descendant of the sea tide

Irish
Hutchison

Son of Hutchin, a diminutive of Hugh

Scottish

I

Inglis

Ethnic name meaning Englishman

Scottish
Innes

Habitational name from Moray, island or river meadow

Scottish
Irvine

Habitational name from Ayrshire, green river

Scottish

J

Jack

From the medieval personal name Jack, a pet form of John

Scottish
Jamieson

Son of Jamie, Scottish pet form of James

Scottish
Johnston

Habitational name from Dumfriesshire, John's settlement

Scottish
Joyce

Norman origin, from Breton personal name Iodoc, lord

Irish

K

Kane

From Ó Catháin, descendant of Cathán, little battle

Irish
Kavanagh

From Caomhánach, follower of Saint Caomhán, gentle

Irish
Keane

From Ó Céin, descendant of Cian, ancient or enduring

Irish
Kearney

From Ó Cearnaigh, descendant of Cearnach, victorious

Irish
Kearns

From Ó Céirín, descendant of Céirín, little dark one

Irish
Keating

Norman origin, from Cétyn, or Welsh Cethin, dusky

Irish
Kehoe

From Mac Eochaidh, son of Eochaidh, horseman

Irish
Keith

Habitational name from East Lothian, possibly wood

Scottish
Kelleher

From Ó Céileachair, descendant of Céileachar, companion loving

Irish
Kelly

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

Irish
Kennedy

From Ó Cinnéide, descendant of Cinnéidigh, helmeted head

Irish
Kenny

From Ó Cionaoith, descendant of Cionaodh, born of fire

Irish
Keogh

From Mac Eochaidh, son of Eochaidh, horseman

Irish
Kerr

From Old Norse kjarr, meaning marshy brushwood

Scottish
Kidd

Nickname from a young goat, for a frisky person

Scottish
Kirkpatrick

Habitational name meaning church of Saint Patrick

Scottish
Kirwan

From Ó Ciardhubháin, descendant of the black dark one

Irish

L

Laing

Scots form of Long, nickname for a tall man

Scottish
Lamont

From Old Norse lögmaðr, meaning lawman

Scottish
Larkin

From Ó Lorcáin, descendant of Lorcán, fierce

Irish
Lawlor

From Ó Leathlobhair, descendant of the half leper

Irish
Leahy

From Ó Laochdha, descendant of the heroic one

Irish
Leslie

Habitational name from Aberdeenshire, possibly garden of hollies

Scottish
Lindsay

Habitational name from Lindsey in Lincolnshire

Scottish
Livingstone

Habitational name from West Lothian, Leving's settlement

Scottish
Lockhart

From Germanic personal name Locard, or a lock keeper

Scottish
Logan

Habitational name from Gaelic lagan, little hollow

Scottish
Lynch

From Ó Loingsigh, descendant of the seafarer

Irish
Lyons

From Ó Liatháin, descendant of Liathán, grey one

Irish

M

MacArthur

Son of Arthur, possibly meaning bear

Scottish
MacAulay

Son of Amhalghaidh, or Norse Olaf, ancestor's relic

Scottish
MacCallum

From Gaelic Mac Coluim, son of Columba, the dove

Scottish
MacDonald

Son of Donald, meaning world ruler

Scottish
MacDougall

Son of Dougal, the dark stranger

Scottish
MacEwan

Son of Ewan, born of the yew

Scottish
MacFarlane

Son of Parlan, Gaelic form of Bartholomew

Scottish
MacGregor

Son of Gregor, meaning watchful

Scottish
MacInnes

From Gaelic Mac Aonghuis, son of Angus

Scottish
MacIntosh

From Gaelic Mac an Toisich, son of the chief

Scottish
MacIntyre

From Gaelic Mac an tSaoir, son of the carpenter

Scottish
Mackay

From Gaelic Mac Aoidh, son of Aodh, fire

Scottish
Mackenzie

From Gaelic Mac Coinnich, son of the fair one

Scottish
Mackie

From Gaelic Mac Aoidh, son of Aodh, fire

Scottish
MacKinnon

From Gaelic Mac Fhionghuin, son of the fair born

Scottish
MacLachlan

Son of Lachlan, from the land of the lochs

Scottish
MacLaren

From Gaelic Mac Labhrainn, son of Laurence

Scottish
MacLean

From Gaelic Mac Gille Eathain, son of John's servant

Scottish
MacLennan

From Gaelic Mac Gille Fhinnein, son of Saint Finnan's servant

Scottish
MacLeod

Son of Leod, from Old Norse Ljótr, ugly

Scottish
MacMillan

From Gaelic Mac Maoláin, son of the tonsured one

Scottish
MacNeil

Son of Niall, meaning champion

Scottish
MacPherson

From Gaelic Mac a' Phearsain, son of the parson

Scottish
MacRae

From Gaelic Mac Rath, son of grace

Scottish
Madden

From Ó Madáin, descendant of Madán, little dog

Irish
Magee

From Mac Aodha, son of Aodh, meaning fire

Irish
Maguire

From Mag Uidhir, son of Odhar, dun coloured

Irish
Maher

From Ó Meachair, descendant of Meachar, hospitable

Irish
Malcolm

From Gaelic Maol Choluim, servant of Saint Columba

Scottish
Malone

From Ó Maoileoin, descendant of Saint John's devotee

Irish
Maloney

From Ó Maoldhomhnaigh, descendant of the church servant

Irish
Matheson

Son of Matthew, or Gaelic Mac Mhathain, son of the bear

Scottish
Maxwell

Habitational name from Roxburghshire, Maccus's pool

Scottish
McCabe

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

Irish
McCann

From Mac Cana, son of Cana, wolf cub

Irish
McCarthy

From Mac Cárthaigh, son of Cárthach, loving

Irish
McCormack

From Mac Cormaic, son of Cormac, chariot lad

Irish
McDermott

From Mac Diarmada, son of Diarmaid, free man

Irish
McDonagh

From Mac Donnchadha, son of Donnchadh, brown warrior

Irish
McDonnell

From Mac Domhnaill, son of Domhnall, world ruler

Irish
McEvoy

From Mac Fhíodhbhuidhe, son of the woodsman

Irish
McGee

From Mac Aodha, son of Aodh, fire

Irish
McGovern

From Mag Shamhradháin, son of Samhradhán, summer

Irish
McGowan

From Mac an Ghabhann, son of the smith

Irish
McGrath

From Mac Craith, son of Craith, grace or prosperity

Irish
McGuinness

From Mag Aonghusa, son of Aonghus, one choice

Irish
McHugh

From Mac Aodha, son of Aodh, meaning fire

Irish
McKenna

From Mac Cionaoith, son of Cionaodh, born of fire

Irish
McKeown

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

Irish
McLaughlin

From Mac Lochlainn, son of the Viking or Norseman

Irish
McLoughlin

From Mac Lochlainn, son of the Norseman

Irish
McMahon

From Mac Mathghamhna, son of the bear

Irish
McManus

From Mac Maghnuis, son of Magnus, great

Irish
McNally

From Mac an Fhailghigh, son of the poor man

Irish
McNamara

From Mac Conmara, son of the hound of the sea

Irish
Meehan

From Ó Miadhacháin, descendant of the honourable one

Irish
Melville

Norman origin, from Malleville in Normandy, bad town

Scottish
Menzies

Norman origin, from Mesnières in Normandy

Scottish
Millar

Scots spelling of Miller, a mill worker

Scottish
Milne

Dweller or worker at a mill

Scottish
Moffat

Habitational name from Dumfriesshire, long plain

Scottish
Molloy

From Ó Maolmhuaidh, descendant of the noble chief

Irish
Monaghan

From Ó Manacháin, descendant of Manachán, little monk

Irish
Montgomery

Norman origin, from Sainte-Foy-de-Montgommery

Scottish
Mooney

From Ó Maonaigh, descendant of Maonach, wealthy

Irish
Moran

From Ó Móráin, descendant of Mórán, great one

Irish
Moriarty

From Ó Muircheartaigh, descendant of the sea navigator

Irish
Morrison

Son of Maurice, or Gaelic Mac Gille Mhoire

Scottish
Muir

Dweller on a moor, Scots form

Scottish
Mulcahy

From Ó Maolchathaigh, devotee of Saint Cathach

Irish
Munro

Possibly from Gaelic bun Rotha, mouth of the Roe

Scottish
Murphy

From Ó Murchadha, descendant of Murchadh, sea warrior

Irish
Murray

From Ó Muireadhaigh, descendant of Muireadhach, lord or master

Irish

N

Nolan

From Ó Nualláin, descendant of Nuallán, famous champion

Irish

O

O'Brien

Descendant of Brian, high king, meaning noble

Irish
O'Connell

From Ó Conaill, descendant of Conall, strong as a wolf

Irish
O'Connor

From Ó Conchobhair, descendant of Conchobhar, hound lover

Irish
O'Doherty

From Ó Dochartaigh, descendant of the hurtful one

Irish
O'Donnell

From Ó Domhnaill, descendant of Domhnall, world ruler

Irish
O'Keeffe

From Ó Caoimh, descendant of Caomh, gentle or kind

Irish
O'Leary

From Ó Laoghaire, descendant of the calf keeper

Irish
O'Malley

From Ó Máille, descendant of Máille, a Mayo chieftain

Irish
O'Neill

From Ó Néill, descendant of Niall, champion

Irish
O'Reilly

From Ó Raghailligh, descendant of Raghallach, possibly valiant

Irish
O'Shea

From Ó Séaghdha, descendant of Séaghdha, hawk-like

Irish
O'Sullivan

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

Irish

P

Paterson

Son of Patrick, meaning nobleman

Scottish
Power

From Norman le Poer, the poor man or pauper

Irish

Q

Quinn

From Ó Cuinn, descendant of Conn, chief or wisdom

Irish

R

Reid

Nickname for someone with red hair

Scottish
Reilly

From Ó Raghailligh, descendant of Raghallach

Irish
Robertson

Son of Robert, meaning bright fame

Scottish
Ross

Habitational name from Gaelic ros, promontory

Scottish
Russell

From Old French rous, nickname for red hair

Scottish
Ryan

From Ó Riain, descendant of Rian, little king

Irish

S

Scott

Ethnic name for a Gaelic speaker from Scotland

Scottish
Shaw

From Gaelic sithech, meaning wolf, or a small wood

Scottish
Sheehan

From Ó Síodhacháin, descendant of the peaceful one

Irish
Sinclair

Norman origin, from Saint-Clair-sur-Elle

Scottish
Stevenson

Son of Steven, meaning crown

Scottish
Stewart

Occupational name for a steward of the royal household

Scottish
Sullivan

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

Irish
Sutherland

Regional name for the southern land of the Norse

Scottish
Sweeney

From Mac Suibhne, son of Suibhne, pleasant

Irish

T

Thomson

Son of Thomas, meaning twin

Scottish

W

Wallace

Ethnic name for a Welsh or Strathclyde Briton

Scottish
Walsh

From Breathnach, meaning Welshman or Briton

Irish
Whelan

From Ó Faoláin, descendant of Faolán, little wolf

Irish

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Scott

Ethnic name for a Gaelic speaker from Scotland

Scottish
Fitzgerald

Norman patronymic, son of Gerald, spear rule

Irish
Hepburn

Habitational name from Northumberland, high burial mound

Scottish
Gilmour

From Gaelic Gille Moire, servant of the Virgin Mary

Scottish
Lawlor

From Ó Leathlobhair, descendant of the half leper

Irish
Sinclair

Norman origin, from Saint-Clair-sur-Elle

Scottish

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Devotional names: Gille, Maol and the saints

A striking group of Gaelic names grew from religious devotion. Gille meant servant or follower, so Mac Gille Chriosd, son of the servant of Christ, became Gilchrist, Mac Gille Easpaig, son of the bishop's servant, became Gillespie, and Mac Gille Mhoire, son of the servant of Mary, became Gilmore. Many of these names begin with Gil or Kil in English, because the Mac at the front was worn away in everyday speech.

Irish used maol in a similar way. The word first meant bald or tonsured, like a monk, and came to mean devotee. Ó Maoil Eoin, descendant of the devotee of Saint John, became Malone, and names like Mulholland and Mulcahy carry the same root, where Mul is the English trace of maol. Irish surnames were among the first hereditary surnames in Europe, taking shape from around the 10th century, and these names show how strongly the early church shaped them.

Where Gaelic last names cluster in Ireland and Scotland

Irish names still follow old territories. O'Sullivan, McCarthy and O'Donoghue are strongest in Munster, O'Neill, O'Donnell and Gallagher in Ulster, O'Connor and O'Malley in Connacht, and Kavanagh and Byrne in Leinster, where the O'Byrnes held the Wicklow mountains. These patterns reflect where each family group held land in the Middle Ages, and even after centuries of emigration many names remain most common close to their medieval homeland.

In Scotland, clan territory tells a similar story. MacLeods held Skye and Lewis, MacNeils held Barra, Camerons held Lochaber and the MacDonalds spread across the Isles and the west coast. Many Scots with other names were linked to a clan as a sept, a family that followed a chief without sharing his name. Clan maps are useful for writers who want a character to come from a real glen or island rather than a vague Highland setting.

Restoring the Ó and Mac, and searching the list

Under English rule many Irish families dropped the Ó and Mac, so Ó Ceallaigh often became plain Kelly and Ó Briain became Brien. From the late 1800s the Gaelic Revival encouraged families to restore the prefixes, which is why O'Kelly, O'Brien and O'Connor are familiar again today. Some people now use the full Irish form, such as Ó Briain, on official documents, and Irish state records accept the Irish spelling with its accents.

In the list, names are spelled the common English way, with the Gaelic original given in the meaning. Because Mac, Mc and M' are variants of one word, search for the part after the prefix to find related forms together. A Scottish name may also turn up in Ireland, since Gaelic speakers crossed the North Channel in both directions for centuries. The generator below the list gives you random picks if you want a quick shortlist.

Frequently asked questions

What are some well known Gaelic last names?

Irish examples include Murphy, Kelly, O'Brien, O'Sullivan, Byrne and Gallagher, and Scottish examples include MacDonald, MacLeod, Campbell, Cameron and MacKenzie. Each is an English spelling of a Gaelic original, such as Ó Murchadha for Murphy or MacDhòmhnaill for MacDonald.

What does Gil or Kil at the start of a name mean?

It usually comes from gille or giolla, meaning servant or follower, often of a saint. Gilchrist points to a servant of Christ, Gilmore to a servant of Mary, Gillespie to a servant of the bishop and Kilpatrick to a follower of Saint Patrick. The Mac that once came first was lost in English.

Why did some Irish families add the O' back?

During the Gaelic Revival of the late 1800s and early 1900s, interest in the Irish language and identity grew, and many families restored the O' or Mac their ancestors had dropped. That is why records from one generation may show Connor and the next O'Connor.

What is a sept?

In Scotland a sept is a family linked to a clan without bearing the chief's name, often through land, marriage or protection. In Ireland the word describes a group of families descended from a common ancestor within a larger territory. Both meanings help explain why names cluster by region.