Where does the name Ong come from

Irish surnames - origin and meaning

Irish surnames? Most people immediately think of Ó’Connor, but also Murphy, Brennan or Walsh. But where do these names come from and what is the meaning behind them? And what is this Ó all about? Irish surnames reflect Ireland's eventful history: Vikings and Normans have left their mark, as have kings and heads of families. Most of Irish surnames have been simplified and translated into an English spelling over the years. But many of them still show the original meaning of the word.

Irish surnames - their origins

Gaelic roots - Mac, Ó and Ní

Irish surnames are used, like almost everywhere else, to distinguish people from one another. They help everyone to know which John or which Mary we are talking about. And that's why names arose in Ireland that identified people on the basis of different characteristics. It could be a quality, or appearance, such as hair color - or ancestry. The Ó in front of the Irish surname means grandson. In this case, Ó’Connor is Connor’s grandson. But wait, it's not that simple. Because that Ó only came into play later. Originally it all started with Mac - that is a syllable that today we mostly associate with Scotland, but which was also used in Ireland.

Mac means son and Mac Arthur means Arthur's son in this case. With Ó things are a little different, because it goes beyond the immediate family. It identifies someone as a descendant of an important person - so the real grandpa is not meant in most cases. Often the Ó is not just followed by the name of the ancestor, but a quality or profession such as Ó Gobhann, which means descendant of the blacksmith.

But what about the daughters? Are they called Mac too? Originally not. Because women have their own prefix in Irish: In Gaelic names, the feminine form is Ní, which means daughter. An example is Siobhán Ní Arthur - Siobhán, the daughter of Arthur.

So many Irish names have Gaelic origins and have changed over the centuries - and adapted to the English language.

Norman and Nordic names

But that does not apply to all names on the Emerald Isle. Because many conquerors, such as the Normans, the Northmen or the English, have also left their mark on Irish surnames. Names that begin with the syllable “Fitz” come from the Normans and refer to the French “Fils”, which also means son. Fitzgerald or Fitzpatrick are good examples of this.

What do the Irish surnames mean?

In the following we introduce you to five of the most common Irish surnames and their origins.


This Irish surname is among the ten most widely used in Ireland - and it's one of the best known. It developed from the Gaelic ‘Ó’Conchobhair’ or ‘Ó’Conchúir’, which means fighter, hero or protector of fighters.

But not all Connors or Ó’Connors belong to the same clan. Because Connor was also a popular first name. Best known are the Connacht O'Connors. They are descended from the famous Conchobhar, King of Connacht. This was a direct ancestor of the last two High Kings of Ireland: Turlough Ó’Connor and Roderick Ó’Connor. Most of the Ó’Connors can be found in the Kerry, Limerick and Cork area.


This is also one of the most common Irish surnames. It is the English version of three different Gaelic names: Ó Braonáin, from the Gaelic word braonwhat sorrow means. And Mac Branáin and Ó Branáin, both from the Gaelic word bran originate, which means something like raven and maybe meant someone with raven hair.

Most of the Ó ’Braonains clan were in Leinster while the MacBrennans lived in County Roscommon. The first written mention of the name comes from 1159, when the MacBranain are mentioned as the leaders of County Roscommon. Today there are families named Brennan practically all over Emerald Isle.


Murphy is the most common Irish surname. This applies to the Green Island itself, but the name is also widespread in the USA. This goes back to the many Irish emigrants. It is an English version of the Gaelic names MacMurchadha and O’Murchadha. Both come from the Irish first name Murchadh. This means something like warriors of the sea and is very likely to go back to the occupation by the Vikings. Because it is quite possible that the first bearer of the first name lived up to his name and actually fought against the invaders at sea.

The most famous clan are the Ui Murchadha from Wexford, who get their name from Murchadh or Murrough, the grandfather of Dermot MacMurrough. This was King of Leinster. John Murphy (1700-1770), better known as Sean O ’Murchadha na Raithineach, was the last leader of the famous bards of Blarney Castle.


This Irish surname is also common on the Emerald Isle. And it's considered an old Irish name that didn't come about through any outside influence. The Gaelic version is Ó’Coileáin, which means something like young dog.

The name Collins probably originally comes from Limerick, where the clan had the Barony of Connello under their rule. But when the Normans invaded Ireland, the family fled to Cork. Today in Ireland there are no castles or the like bearing the name Collins.


The name Doyle is believed to have come from the Northmen. The Gaelic name is Ó’Dubhghaill, which means something like dark stranger. A name with which the Vikings, above all the dark-haired Danes, were called at that time. Perhaps the name was also used to distinguish the Danes from the lighter-haired Norwegians.

This famous name is one of the oldest in all of Ireland - and one of the most common too. It is said that the ancestor who passed this name on came from a Viking who settled early in Ireland.

Here you can read more about Irish first names.