{"id":34733,"date":"2018-08-03T10:50:30","date_gmt":"2018-08-03T14:50:30","guid":{"rendered":"https:\/\/blog.genealogybank.com\/?p=34733"},"modified":"2026-03-02T11:13:14","modified_gmt":"2026-03-02T16:13:14","slug":"irish-last-names-their-meanings","status":"publish","type":"post","link":"https:\/\/www.genealogybank.com\/blog\/irish-last-names-their-meanings.html","title":{"rendered":"Irish Last Names & Their Meanings"},"content":{"rendered":"

Irish Americans proudly display their heritage in their last names. The Kelly\u2019s, the Murphy\u2019s, the O\u2019Connor\u2019s and the Byrne\u2019s \u2013 such names bring to mind the clans of old, the heady days of warring kerns and heroic galloglaighs. But where did these names come from? What is the story behind the Irish surnames that so many Americans carry to this day?<\/p>\n

\"Photo:<\/a>
Photo: Ben Bulben, County Sligo, Ireland. Credit: Jon Sullivan; Wikimedia Commons.<\/figcaption><\/figure>\n

First Names First<\/strong><\/p>\n

Before understanding Irish last names, it is essential to remember that first names have meanings all their own. For example, look at the Irish surname O\u2019Brian. The O has a meaning that we will cover below, but what about the Brian part? Such commonly used names should not be taken for granted, because they provide a key to our ancestors. Somewhere down the O\u2019Brian genealogy line was the original Brian, himself. No O. Just Brian. The same goes for the original Donnell of the MacDonnells and the first Allen of the McAllens. The descendants of Brian (meaning \u201cnoble\u201d), of Donnell (meaning \u201cworld-mighty\u201d), and Allen (meaning \u201chandsome\u201d) remember that somewhere down the line their ancestor earned or was given that name.<\/p>\n

The O\u2019s, the Mac\u2019s, the Mc\u2019s and the Fitz<\/strong><\/p>\n

In the old country, in the days of yore, a person was not so much defined by who they were but by where they came from, who their father was, or their trade. The uppermost heights that a son could gain were the same as those of his father or grandfather.<\/p>\n

The Mc in \u201cMcDonnell\u201d and the Mac in \u201cMacDonough\u201d all mean \u201cson of\u201d in the native Gaelic, and all have survived and flourished as common prefixes to Irish surnames (though the original Mac is more common in Scotland). The feminine form, nic (meaning \u201cdaughter of\u201d) is a rarity in modern Irish last names, which reflects the patriarchal society.<\/p>\n

Son of\u2026<\/strong><\/p>\n

Patrick, son of Brian, or Patrick mac Brian, was the given formula for how Irishmen would first describe themselves in the Middle Ages. In the meantime, Brian, the father of Patrick, would be known as Brian mac Connor, or the son of his own father, Connor. Mac \u2013 sometimes shortened to Mc \u2013 was said after the man\u2019s given name and before the name of his father, denoting his male parentage. This method generally told enough of an Irishman\u2019s story to identify him from others.<\/p>\n

Unlike in modern times, where surnames are very much essential to our identity in day-to-day life, the early Irish rarely needed to use them. The fact was, in an isolated, tribal society (known as \u201ctuaths\u201d) where everyone came from the same place and very little family history was recordable, it just made more sense to say who your father was rather than give your ancestral line. Thus, Patrick, Brian, and Connor would all have different surnames (surnames meaning: sired by) as each of their fathers would probably have a different given name (though names such as \u201cPatrick mac Patrick\u201d did occur, i.e., junior).<\/p>\n

Due to this generational change from one surname to another, it is difficult to trace Irish last names into the medieval period. However, like society itself, the tradition of Irish last names changed with the times. Feudalism, Catholicism, foreign invasions and intertribal wars brought pride in one\u2019s lineage very much into vogue. Having an ancestor who was a landed lord, being the descendant of a saint, or someone in the line of ancient kings became incredibly important to the upper classes of medieval Irish society.<\/p>\n

The First Irish Surname<\/strong><\/p>\n

The first Irishman with a recorded last name, Tigherneach\u00a0Ua Cleirigh, was a lord who died in 916 C.E. in what is now modern-day Galway. The Ua denotes Tigherneach as being either the \u201cson of,\u201d \u201cgrandson of,\u201d or \u201cdescendant of\u201d Cleirigh (modern: Clery). The Ua would later become the O we are all familiar with in such names as O\u2019Connell or O\u2019Leary. This change to \u201cgrandson of\u201d or \u201cdescendant of\u201d is an important departure from simply saying \u201cson of,\u201d as it alters the narrative of a person\u2019s name from \u201cthis is my dad\u201d to \u201cthis is my family.\u201d The most widely seen example of this comes from the name O\u2019Brian, denoting a descendant of the legendary King Brian Boru\u2026 or giving a coincidental bit of luster to those with a different ancestor named Brian.<\/p>\n

The Fitz<\/strong><\/p>\n

It would be the feudal lords and barons that first took on the mantle of Irish surnames to denote their familial lineage, and no one brought the hammer of feudalism quite like the Normans. In 1169 C.E. they invaded Ireland in a stunning sequel to their invasion of England in 1066, bringing with them their particular blend of oppression and progress. To say it was a rough go for anyone under the Norman boot is an understatement, but it is also how Irish surnames gained the prefix Fitz, as in Fitzpatrick. This Latinized form of \u201cson of\u201d is still a popular prefix found in Irish last names. Not only that, but the Normans \u2013 and, more so, their English successors \u2013 altered the \u201cson of\u201d formula that had heretofore been the most common source of surnames in Ireland.<\/p>\n

Irish Occupational Surnames<\/strong><\/p>\n

\u201cSmith\u201d is an incredibly common name in the English-speaking world. But who was this Smith? What did he or she do that was so magnificent to have so many modern ancestors still proudly bearing their namesake? Well, in a word: they smithed. They were blacksmiths, locksmiths, gunsmiths, goldsmiths, etc. In medieval England what a person did, or what their family business was, often determined their last name. This is why there are still so many Archers, Cooks, Coopers, Masons, Thatchers, Fishers, Butlers, and Wrights in England and, since the English occupation, in Ireland.<\/p>\n

Such occupational surnames were fairly common in the early Irish lexicon, especially considering that specialized occupations were commonly passed down from parent to child. Irish surnames like O\u2019Leary (from \u00d3 Laoghaire, meaning calf-herder) or McLoughlin (from Mac Lochlainn, meaning Viking) tell the tale of sons who followed in the footsteps of their fathers. In fact, it wasn\u2019t until the Normans and English established their feudal fiefdoms on the island and the markets and cities began to grow, that such names began to become invaluable. These last names immediately told a lord or merchant what you did and how you could help them. Think of them as business cards built into a name, an effective and subtle marketing tactic that a journeyman worker or skilled artisan would have been a fool to pass up.<\/p>\n

Irish Toponymic Surnames<\/strong><\/p>\n

Trade brought toponymic last names to Ireland. Brian of Bray would become Brian Bray, while William from Wales became William Walsh. Barring a few examples, these names are not typical in Ireland, as strangers in a strange land \u2013 especially in less than tolerant times \u2013 are more inclined to assimilate rather than celebrate their differences. However, this is not the case with those who conquered\u2026<\/p>\n

Anglicization: How Irish Last Names Changed<\/strong><\/p>\n

By the 1500s, traditional Irish Catholicism was put down in favor of English Protestantism and much of the native Irish population was resigned to second-class citizenship. This forced the Irish to Anglicize, to adapt and become more like their conquerors in order to survive these times. This is why so many Irish names have evolved beyond their Gaelic origins to fit more easily into the English language, some dropping the classic prefixes while others translated completely. Thus, \u00d3 Ceallaigh became Kelly, \u00d3 Murchadha became Murphy, while Mac Gabhann (the Irish occupational last name for a smith) became Smith.<\/p>\n

The traditional Gaelic names changed under English rule. Anglicization became a way of survival for many Irish people during the last five centuries and resulted in the Irish surnames we all know today.<\/p>\n

10 Common Irish Last Names & Their Meanings<\/strong><\/p>\n

Below are some of the most common Irish last names not discussed above. Our family history research is often guided by our surnames. Find your Irish last name in the list below or use our surname meaning<\/a> search to find your name and learn more about your Irish heritage.<\/p>\n