St. Patrick's Day: 10 most Irish surnames in the world

Today is March 17 and the world looks a little bit greener. Why, you ask? Obviously because its St. Patrick's Day!

Who doesn't love celebrating Ireland's patron saint with a pint of the black stuff?

And who doesn't love using this day especially to tell everyone exactly how Irish you really are?

In honour of such a magical day, we have rounded up 10 of the most common surnames, for you to see how Irish your surname really is.

1. O'Sullivan

In Irish, O'Sullivan is written Ó Súilleabháin. It is the third most common surname and 80 per cent of people with this name belong to the counties of Cork and Kerry. The family name goes all the way back to around 1600 BC and is Irish Gaelic for the descendants of "One-Eye", which was possibly used to scare away rivals. Today, the name is so common in Ireland that people need to use nicknames to designate families.

Fun fact: all Sullivan's descended from one man, making it one of the oldest, most abundant family names in Europe.

2. O'Brien

All hail the king! If you have this name, you are most likely a descendant of Brian Boru, who was King of Ireland in the 10th century.

But this Brian was no ordinary king; he had an extremely successful career, fought many brave battles and it is actually his harp (he was fond of music) that has now become the model for the national emblem of Ireland.

Recognise it from anywhere? Yep, that's right it's also the Guinness emblem.

3. O'Connor

O'Connor derives from the Irish Ó Conchobhair, which means "lover of hounds", "wolf-lover" or "patron of warriors". There were at least five unrelated Ó Conchobhair families originally, located in Kerry, Cork, Offaly, Clare and Roscommon.

Whether or not they owned pet wolves is not known...

4. Kelly

While Kelly is the second most common surname in Ireland today, the origin of the name remains uncertain. But, some historians believe it is derived from O'Ceallaigh, meaning "bright-headed" or "troublesome".

Fun fact: Grace Kelly, otherwise known as the Princess Grace of Monaco was of Irish decent.

5. Murphy

Murphy is actually the most common surname in Ireland and is also very abundant in America. It is the anglicised version of two Irish surnames put together, MacMurchadha and O'Murchadha, both of which derive from the Irish name Murchadh, meaning "sea-warrior".

6.O'Neill

O'Neill most likely stems from the name "Niall", which means "passionate" or "vehement". This family is really old, dating all the way back to 360 AD.

It is believed they are actually a descendant from the royal family of Tara, who were monarchs of all of Ireland from the 5th to the 17th century. Time to practice that royal wave.

7. Smith

Did you know that Smith is the most ordinary name in the world?

It is so ordinary in fact, that it is the fifth most common surname in Ireland, the most common last name in England, Scotland and Wales AND is also very common in countries like Germany, Canada and Australia.

In Irish, Smith comes from "Man an Gabhain" (Gaelic form is MacGabhain), which translates into "son of smith". The vast majority of Smith families come from the Cavan county.

8. Walsh

The fourth most common surname in Ireland, the Walsh name can be found pretty much in any county. It comes from – you guessed it – Welsh people who came to Ireland during the Anglo-Norman invasions in 1171.

The name is even pronounced "Welsh" in some counties like Munster and Connaught.

9. Byrne

This is a variant of the Irish Ó'Broin, meaning descendants of Branach, meaning "raven". Bran was the king of Leinster, who died in 1052.

Anyone else have to think of Bran Stark from Game of Thrones here?

10. Ryan

Ryan has various possible origins. Some believe it stems from Ó Ruaidhín, which means "little red one", while others believe it is a simplification of the name Mulryan, which means "little king".

The first recorded spelling of the name dates back all the way to the 14th century.

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