About this Irish name generator
An Irish name is a register. 'Aoife Ní Shúilleabháin' commits to modern Republic of Ireland bilingual Irish-language Catholic-cultural professional. 'Bridget Connors' commits to Mincéirí Traveller Community Catholic-observant adult-learner. 'James Crawford' commits to Northern Ireland Protestant / Unionist Ulster Scots Presbyterian commercial-law. Most online Irish-name generators collapse all of these into a single 'O'Reilly-and-Murphy' stage-Irish paste. This Irish name generator doesn't, and that is what it is built for.
Each result draws on real Irish onomastic scholarship — the medieval Brehon-Law clan-and-patronymic system (Mac- / Ó-), the late-medieval Norman-Gaelic assimilation (Burke / Fitzgerald / Roche), the penal-era anglicisation that dropped the Mac- and Ó- prefixes, the modern Republic's Irish-language revival, the distinct Northern Ireland Catholic / Nationalist and Protestant / Unionist registers, the Ulster Scots tradition, the Mincéirí / Pavees Travelling Community onomastic tradition, and the substantial Irish-American / Australian / British-Irish diaspora communities.
The registers the generator rotates
Medieval Gaelic: 600-1200 CE, Brehon-Law, Mac- / Ó- + clan.
Late medieval / Norman-Gaelic: 1200-1600 CE, Norman surnames adopted.
Penal-era Anglo-Irish: 1690-1840, Mac- and Ó- formally dropped.
Modern Republic of Ireland: 1922-present, Irish-language revival.
Northern Ireland Catholic / Nationalist: Ó- preserved or anglicised.
Northern Ireland Protestant / Unionist: Scots-Irish, Old Testament given names.
Ulster Scots: Lowland Scots given names + surnames.
Travelling Community / Mincéirí: Catholic saint-name + Traveller surname.
Irish-American diaspora: Anglicised, saint-name + Boston / Chicago / NYC.
Irish-Australian / Canadian / British-Irish diaspora: Anglicised with regional flavour.
How Ó, Mac, Ní, and Nic work
An Irish surname is built from a relationship word. Mac means 'son of'; Ó means 'grandson' or, more loosely, 'descendant of.' So Mac Cárthaigh is 'son of Cárthach' and Ó Súilleabháin is 'descendant of Súileabhán.' The piece that trips up most generators is the feminine. A woman does not take Mac or Ó. A daughter of an Ó- family becomes Ní, a contraction of iníon Uí, 'daughter of the descendant of'; a daughter of a Mac- family becomes Nic, from iníon Mhic. That is why the generator returns Aoife as Ní Shúilleabháin rather than Ó Súilleabháin, and why the surname's first consonant softens to add that 'h' (Súilleabháin becoming Shúilleabháin) — Irish lenites the name after these particles.
Then there is the history layer the generator rotates through. Under the Penal Laws and the long anglicisation that followed, a great many families dropped the Ó and Mac entirely: Ó Ceallaigh flattened to Kelly, Mac Gabhann to Smith or McGowan, and the apostrophe in O'Brien is really an English printer's attempt at the Irish fada over the Ó. After independence in 1922 many families restored the Gaelic form, which is why a single bloodline can hold Ó Súilleabháin, O'Sullivan, and Sullivan across three generations. Picking a register is therefore also picking a moment in that long swing between Irish and English forms.
What you get
Each result returns a full Irish name (with bilingual Irish-and-English forms where relevant), a pronunciation note (respecting Irish-language phonology where applicable), an etymology + register + historical period paragraph, a backstory (place of birth, family, profession, generation), a daily-life paragraph (languages spoken, religious or secular practice, sport followed, drink of choice), and a current situation a writer or GM can use.
How to use the names
For historical fiction set in any Irish period — Brehon-era Munster, Norman Connacht, Penal-era Cork, 1916 Dublin, Troubles-era Belfast, contemporary Limerick — the names plug in directly with their period-appropriate register. For contemporary fiction, the modern Republic, Northern Ireland (both registers), Traveller Community, and diaspora registers are all distinct and each works without adjustment. For Celtic-inspired fantasy roleplaying (D&D's Tír na nÓg-style settings, Pathfinder's Iobaria, Glorantha's Esrolia-as-Celtic-analogue), the medieval Gaelic register integrates cleanly.
Why register matters more than 'Irishness'
A Cork doctor in Dublin in 2026, a Lisburn solicitor in London, a Limerick Traveller community sociologist, and a 12th-century Eóganacht Chaisil princess are four genuinely different cultural artefacts even though all four are Irish. The generator commits to one register per result, gives you the cultural-specific structure and the small details (tea preference, mass observance, sport followed) that distinguish the register, and produces a character whose dignity is specific to that register rather than to a generic 'Irish' archetype.