O’Sullivan: surname meaning, origin, and popularity, explained

Like so many other Irish family names or surnames with Irish origins, O’Sullivan comes with an extraordinary history. From the story behind its origins to the meaning of the family crest, we are going to find out what it’s all about.

O’ Sullivans out there, raise your hands. Let’s delve into the O’Sullivan surname meaning, origin, and popularity, explained.

O’Sullivan surname – where does it come from?

The O'Sullivan surname was first found in Cahir, Tipperary.
Credit: commons.wikimedia.org

O’Sullivan, pronounced ‘o-sull-i-van’, and Sullivan together form the third most popular surname in Ireland, most predominantly in counties Cork and Kerry.

It was first found in County Tipperary, in the territory of Cahir. The surname is of Irish origin, and comes from the original Irish version, Ó Súilleabháin. The name descended from Eoghan Mor.

In Irish surnames, the prefix ‘O’ means ‘descendant of’. The ‘suil’ part of the original Irish spelling comes from the Irish word for ‘eye’. O’Sullivan as a whole means, ‘descendant of the hawk’ or ‘dark-eyed one’.

The surname O’Sullivan was first found in the territory of Cahir in County Tipperary, established in the 13th century in south-central Ireland in the province of Munster. This was before the Anglo-Norman Invasion of Ireland.

The O’Sullivan families – branches off of the main O’Sullivan’s

A branch of the O'Sullivan's moved to the Beara Peninsula in Cork.
Credit: Tourism Ireland

The O’Sullivan clan was forced from their original territory in Country Tipperary to County Kerry. This was a result of the Anglo-Norman Invasion of Ireland.

At this point, they divided into several branches. The main ones were the O’Sullivan Mór, the greater branch of the family, who stayed in south Kerry.

The other most notable faction of the family, the O’Sullivan Beare, were in County Cork, the Beara Peninsula, areas of west Cork, and south Kerry.

Carriganass Castle, one of the ancestral castles of the O'Sullivan Beare clan.
Credit: Flickr / y6y6y6

The early O’Sullivan history is characterised by their ongoing feud with their neighbours, the McCarthy’s, in the 1500s. It was in the late 16th century that the O’Sullivan’s prosperity in their feud ended, and the O’Sullivan Beare were further divided.

Along with the help of Spanish forces sent by King Philip, they came up against the English forces. The chieftain of the family clan, Donal O’Sullivan, led his troops. However, the Irish forces lost.

O’Sullivan’s across the world – emigration all over

The O'Sullivan surname is now across the world due to emigration.

Over the years, the O’Sullivan’s have made names all over the world. In France, Colonel Dermot O’Sullivan Mor fought for the Irish Brigades in France in the 1640s.

Furthermore, in an 1881 census, almost half the O’Sullivan’s in England were found in London.

John O’Sullivan of the O’Sullivan Beare’s was one of the first to arrive in the United States. He travelled to Virginia in 1655 and stayed there as a planter.

The O'Sullivan surname is popular across the world.
Credit: commons.wikimedia.org

O’Sullivan’s are found in many other countries all over the world. These include Canada, Australia, and New Zealand.

The colours on the O’Sullivan family coat of arms are red, green, and yellow. The red signifies military fortitude and magnanimity, while the yellow represents generosity.

There are a number of interesting symbols on the coat of arms, including a snake, a sword, and a stag. The green snake on the crest symbolises curiosity. The yellow stag signifies peace and harmony, while the sword symbolises government and justice.

Famous O’Sullivan’s – notable O’Sullivan’s you might know

There are many famous people with the name O'Sullivan.
Credit: Flickr / oneredsf1 and commons.wikimedia.org

You might share a name with some notable famous people with the surname O’Sullivan throughout history.

Maureen O’Sullivan

Maureen O’Sullivan was an Irish-American actress best known for being Tarzan’s Jane in the film franchise between 1932 and 1948.

She was of Irish, English, and Scottish descent, and was born in the 1911 in Boyle, County Roscommon. She is the mother of actress and activist, Mia Farrow.

Gilbert O’Sullivan

Gilbert O’Sullivan is an Irish singer-songwriter from Waterford. Those growing up in the 1970s will remember his success with songs such as ‘Alone Again’, ‘Clair’, and ‘Get Down’.

Ronald Antonio O’Sullivan

Ronnie O'Sullivan is one of the most famous people with this surname.
Credit: commons.wikimedia.org

Any fans of snooker reading this will recognise the name Ronald Antonio O’Sullivan OBE. He is an English professional snooker player, who is the current world number one.

Ronald Antonio O’Sullivan is widely recognised as one of the most talented and accomplished players in the history of snooker. He holds the record for the most ranking titles in professional snooker, with a total of 38 titles.

Notable mentions

Denis O’Sullivan: A retired professional Irish golfer. He won great success in the 1985 Irish Amateur Close and the 1990 Irish Amateur Stroke Play.

Eoghan Rua Ó Súilleabháin (Owen Roe O’Sullivan): Owen Roe O’Sullivan was an 18th century Irish poet and Irish writer, recognised as one of the last great Irish Gaelic poets from Gaelic Ireland.

Other notable mentions with the surname O'Sullivan.
Credit: commons.wikimedia.org

John O’Sullivan: He was a British journalist who coined the term term, “Manifest Destiny”.

Louis Sullivan: Aptly named the “father of skyscrapers”, Louis Sullivan was an American architect due to his great accomplishments in construction and design in the field.

Anne Sullivan: Anne Sullivan was an American teacher in the 19th century. Anne is best known as the woman who broke into Helen Keller’s dark and silent prison.

Gearóid O’Sullivan: He was an Irish teacher, Irish Republican Army officer, Barrister, and Fine Gael politician.

FAQs about the O’Sullivan surname

Murphy is one of the most common Irish-American surnames.
Credit: Flickr / Paul Sableman

Is O’Sullivan Irish or Scottish?

O’Sullivan is most definitely an Irish surname! Although there are some O’Sullivans in Scotland as well as elsewhere around the world.

What are the most common Irish-American last names?

According to history records, the most common Irish-American last names are Murphy, Byrne, Kelly, O’Brien, Ryan, and O’Sullivan, to name a few.

What is the most common surname in Ireland?

The most common surname in Ireland is Murphy, or its Irish equivalent, Ó Murchadha.

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