Gaelic sept

O'Sullivan

Ó Súilleabháin

Also: Sullivan

“descendant of Súildubhán, 'dark-eyed one'”

The sept's historic heartland, highlighted. People moved — a name can be found far from home.

The story

Princes of the Beara peninsula. After Kinsale, Donal Cam O'Sullivan Beare led a thousand followers on a terrible 300-mile winter march to Leitrim — 35 arrived.

Their world Around 1450 — The Gaelic Resurgence. Plague, absentee landlords and Gaelic recovery shrink English Ireland to a fortified strip around Dublin.

See them on the atlas ↗

What the name is made of

Ó Súilleabháin
Ó — descendant of (originally grandson of)
Súilleabháin — the ancestor, trade or place the name is built on

Find this form in the Irish-to-English index → · What Ó and Mac actually mean

Is O'Sullivan an Irish name?

O'Sullivan is a Gaelic name: it was formed in Irish, from an Irish ancestor, before English was spoken here.

The five answers, and why it is rarely yes or no →

From Wikipedia — “O'Sullivan (surname)”

O'Sullivan is a surname of Irish origin. The surname is associated with the southwestern part of Ireland, and was originally found in County Tipperary and Kerry before the Anglo-Norman invasion. It is the third most numerous surname in Ireland. Roughly half of O'Sullivans hail from Ireland, with around 50% of the O'Sullivans residing there.

Read the full article ↗ · Text from Wikipedia, licensed CC BY-SA 4.0.

Neighbours — other names from the same counties

Buckley · Cork, Kerry Cronin · Cork, Kerry Culloty · Kerry, Cork Díaz · Cork, Kerry Dowling · Cork, Kerry Downey · Cork, Kerry Foley · Kerry, Cork Galvin · Kerry, Cork Kelleher · Cork, Kerry McCarthy · Cork, Kerry Moynihan · Kerry, Cork O'Donoghue · Kerry, Cork O'Mahony · Cork, Kerry Riordan · Cork, Kerry

Quick answers

Is O'Sullivan an Irish name?

O'Sullivan is a Gaelic name: it was formed in Irish, from an Irish ancestor, before English was spoken here. In Irish the name is Ó Súilleabháin.

What does the surname O'Sullivan mean?

O'Sullivan (Irish: Ó Súilleabháin) means “descendant of Súildubhán, 'dark-eyed one'”. Origin: Gaelic sept.

Where in Ireland is the surname O'Sullivan from?

The historic homeland of the O'Sullivan name is Cork, Kerry. People moved, so the name can be found far beyond it.

What is the Irish for O'Sullivan?

Ó Súilleabháin. Related spellings: Sullivan.

Looking for the O'Sullivan family crest? Read this first — arms belong to people, not surnames, and the honest version is more interesting. Tracing O'Sullivan ancestors? The step-by-step guide.

Not your spelling? Try the full A–Z. Know more about the O'Sullivan name? Add to the story.