Irish names come from the Irish language, ancient family lines, Christian traditions, mythology, regional history, and centuries of migration. Some are familiar around the world, while others rarely appear outside old records, Irish-speaking communities, or very determined baby-name shortlists.
This directory brings together our complete collection of Irish first names, Irish surnames, name meanings, pronunciations, origins, and alphabetical guides. You can browse more than 1,000 given names, work through Irish last names from A to Z, explore surname history, or find themed collections based on religion, ancestry, popularity, and cultural origin.
Irish names generally fall into two broad groups: given names used for children and family names passed through generations. Many traditional forms were later anglicized, so the same name may appear in Irish and English spellings, sometimes with several regional variations.
Start with our two largest collections if you want to browse widely. The first-name directory contains more than 1,000 Irish given names, while the surname guide brings together Irish family names and their older forms.
These alphabetical guides cover Irish first names for girls, boys, and unisex use. Each directory focuses on a single initial and includes meanings, Irish spellings, and pronunciation help where available.
Irish surnames can point to an ancestor, clan, occupation, physical characteristic, or place of origin. The guides below cover Irish last names from A to Z, including Gaelic forms, meanings, approximate pronunciations, and historical context.
Alphabetical lists are useful when you already know the initial you want. These themed guides are better for exploring a particular period, culture, family background, or naming style.
The popularity guide uses Ireland’s latest official registration figures, while the Catholic collection focuses on names connected with Irish saints, Christianity, biblical traditions, and historic religious figures.
Common and popular are not always identical. A surname may be widely recognized abroad without ranking among the most frequently recorded names in Ireland today. The rare surname guide covers older forms, small family groups, and names now seldom encountered.
Irish family names were shaped by more than Gaelic clan history. Viking settlement, Norman arrival, movement between Ireland and Scotland, anglicization, and migration to North America all left marks on the surnames people use today.
The prefix Ó means “descendant of” in Irish. The apostrophe used in names such as O’Brien and O’Neill belongs to the anglicized English form, while the original Irish spelling uses Ó with a fada.
Some surnames deserve more room than an A–Z entry can provide. These individual guides look at a name’s Irish-language form, meaning, historical origin, regional connections, and family roots.
An Irish name may originate directly in the Irish language, also known as Gaeilge, or it may be a name that became established in Ireland through religion, settlement, literature, or long family use. Not every name used in Ireland began there, and not every Irish-origin name remains common in modern Ireland.
Names such as Aoife, Caoimhe, Oisín, Tadhg, Niamh, Cian, and Saoirse retain a clear Irish-language identity. Other familiar choices, including Patrick, Bridget, John, and Mary, arrived through wider Christian and European traditions but developed a strong place in Irish family life.
People often use “Irish,” “Gaelic,” and “Celtic” as though they mean exactly the same thing. They overlap, but each term covers something slightly different.
A name can therefore be Irish and Gaelic, Irish but not originally Gaelic, or shared across several Celtic cultures. Family history rarely fits into a perfectly tidy box. Genealogy researchers know this already, usually after opening their seventeenth browser tab.
Many Irish names changed spelling under English-language administration. Clerks wrote names according to English phonetics, families adapted spellings after emigration, and prefixes were sometimes removed. This produced several forms of the same underlying name.
For example, Ó Súilleabháin became O’Sullivan or Sullivan, while Ó Ceallaigh became O’Kelly or Kelly. A family may appear under different spellings across parish registers, census returns, passenger records, and civil documents.
Irish pronunciation follows rules that differ from English, so reading a name letter by letter often leads you astray. Aoife is commonly pronounced EE-fa, Caoimhe is often pronounced KEE-va or KWEE-va depending on dialect, and Niamh is pronounced roughly like NEEV.
The fada, the accent used in names such as Seán, Rían, and Órla, can change a vowel’s sound and sometimes distinguish between words. Dropping it may be common in English-language databases, but it is still part of the correct Irish spelling.
The two prefixes most closely associated with Irish surnames are Ó and Mac.
These prefixes became hereditary surname markers, so they refer to a wider family line rather than the literal father or grandfather of every person carrying the name.
Some surnames have strong historical associations with particular counties or provinces. O’Sullivan is closely tied to Munster, especially Cork and Kerry, while O’Donnell has deep roots in Donegal and O’Neill is strongly associated with Ulster.
A surname alone cannot prove that a modern family came from one exact place. Migration within Ireland, plantation, marriage, famine, work, and emigration spread family names far beyond their earlier territories. Use a surname as a genealogy clue, not a complete family tree.
Begin with names, dates, locations, and known relatives before working backward through records. Check alternate spellings, versions without Ó or Mac, and forms that may have been written phonetically.
Useful official resources include the IrishGenealogy.ie civil and church record collections, the National Archives of Ireland census records, and the Placenames Database of Ireland when a surname is connected with a townland or local place.
Traditional Irish first names include Aoife, Niamh, Caoimhe, Áine, Siobhán, Oisín, Tadhg, Cian, Fionn, Ciarán, and Diarmuid. Some remain common in Ireland, while others are used mainly by families seeking a clear Irish-language connection.
Murphy, Kelly, Byrne, Ryan, O’Brien, Walsh, O’Sullivan, O’Connor, Doyle, and McCarthy are among the best-known Irish surnames. Rankings vary by dataset and period, particularly when spelling variants and surnames with removed prefixes are counted separately.
Irish and Scottish names share many Gaelic roots, but the languages, spellings, pronunciations, and historical usage developed differently. Names such as Niall, Aidan, Fiona, and several Mac surnames appear in both traditions, while other names are much more closely associated with one country.
Mac means “son of” in Irish. Mc is a shortened spelling of the same prefix. Neither form automatically indicates whether a family is Irish or Scottish, since both naming traditions use Mac surnames.
O’ comes from the Irish prefix Ó, meaning “descendant of”. In names such as O’Brien, O’Connor, and O’Neill, it identifies the family as descendants of an earlier named ancestor.
Irish names may have an original Irish-language spelling, an anglicized form, regional variants, and simplified spellings used after emigration. Older records also contain phonetic forms created by clerks who did not speak Irish.
Yes. Irish names are used by families in Ireland, members of the Irish diaspora, and people with no direct Irish ancestry. Checking the correct spelling and pronunciation is sensible, particularly for names containing letter combinations or fada marks unfamiliar to English speakers.
This page is the main directory for Ireland Wide’s complete names collection. Use the A–Z lists to search by initial, open the themed surname guides for ancestry research, or browse our individual family-name histories for a closer look at origins, meanings, Irish forms, and regional connections.
We will continue adding newly published name guides here, so this directory remains the central starting point for Irish first names, surnames, baby names, family history, and pronunciation help.
Dan is the founder and editor of Ireland Wide. Born and raised in Ireland, he researches the country’s history, mythology and cultural traditions using museum collections, heritage authorities and historical sources. He leads the site’s editorial team, with a particular focus on distinguishing documented history from later folklore and modern interpretations.
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