A formal Irish name consists of a given name and a surname. In the Irish language, most surnames are patronymic surnames, distinct from patronyms, which are seen in Icelandic names, for example. The form of a surname varies according to whether its bearer is a man, a woman, or a woman married to a man, who adopts his surname.
An alternative traditional naming convention consists of the first name followed by a double patronym, usually with the father and grandfather's names. This convention is not used for official purposes but is generalized in Irish: [[Gaeltachtaí]] (Irish-speaking areas) and also survives in some rural non-Irish: Gaeltacht areas. Sometimes the name of the mother or grandmother may be used instead of the father or grandfather.
See also: Epithet. A first name may be modified by an adjective to distinguish its bearer from other people with the same name. Irish: Mór ("big") and Irish: Óg ("young") are used to distinguish parent and child, like "senior" and "junior" are used in English, but are placed between the given name and the surname, e.g. Irish: Seán Óg Ó Súilleabháin corresponds to "John O'Sullivan Jr." (anglicised surnames often omit, leaving no trace of original Irish: Ó).
The word Irish: Beag ("little") can be used in place of Irish: Óg. This does not necessarily indicate that the younger person is smaller in stature, merely younger than their parent or in some cases to imply a baby was small, possibly premature, at birth.
Adjectives denoting hair colour may also be used, especially informally, e.g. Irish: Pádraig Rua ("red-haired Patrick"), Irish: Máire Bhán ("fair-haired Mary").
Colloquially in Irish: [[Gaeltachtaí]] (Irish-speaking areas) and some other areas it remains customary to use a name formed by the first name (or nickname), followed by the father and the paternal grandfather's name, both in the genitive case, e.g. Irish: Seán Ó Cathasaigh (Seán O'Casey), son of Irish: Pól, son of Irish: Séamus, would be known to his neighbours as Irish: Seán Phóil Shéamuis. Occasionally, if the mother or grandmother was a well-known person locally, her name may be used instead. If the mother's name is used, then the maternal grandfather or grandmother may follow it, e.g. Irish: Máire Sally Eoghain.
This system can be particularly useful for distinguishing people who live in the same area and who share a common surname but are not closely related, e.g. two people named John McEldowney might be known as "John Patsy Dan" and "John Mary Philip" respectively. Even the Irish forms sometimes survive in parts of the Sperrins, so that among the principal families of Glenullin some branches are known by father/grandfather forms such as Irish: Pháidí Shéamais or Irish: Bhrian Dhónaill.
A man's surname is generally formed by Irish: Ó ("descendant"; historically Irish: Ua) or Irish: Mac ("son") followed by a name or definite noun (often a profession) in the genitive case, e.g. Irish: Ó Dónaill (literally "descendant of Dónall") and Irish: Mac Siúrtáin (literally "son of Jordan"). When Irish: Ó is followed by a vowel, a (lowercase) is attached to the vowel, e.g. Irish: [[Ó hUiginn]] (O'Higgins) or Irish: [[Ó hAodha]] (Hughes).
A woman's surname replaces Irish: Ó with Irish: Ní (reduction of Irish: Iníon Uí "descendant's daughter") and Irish: Mac with Irish: Nic (reduction of Irish: Iníon Mhic "son's daughter"). In both cases the following name undergoes lenition, except for when Irish: Nic is followed by or . Thus the daughter of Irish: Seán Ó Dónaill has the surname Irish: Ní Dhónaill and the daughter of a Irish: Pól Mac Siúrtáin has the surname Irish: Nic Shiúrtáin. In Ulster it is common for a woman who adopts her husband name to just use Irish: Ní or Irish: Nic rather than the forms seen below.
If a woman marries a man, she may choose to take his surname. In this case, Irish: Ó is replaced by Irish: Bean Uí ("descendant's wife") and Irish: Mac by Irish: Bean Mhic ("son's wife"). In both cases Irish: Bean may be omitted, which results in Irish: Uí or Irish: Mhic. In both cases the following name undergoes lenition, except for when Irish: Mhic is followed by or . Thus a woman marrying Irish: Seán Ó Dónaill may choose to adopt Irish: Bean Uí Dhónaill or Irish: Uí Dhónaill as her surname and a woman marrying Irish: Pól Mac Siúrtáin may choose to adopt Irish: Bean Mhic Siúrtáin or Irish: Mhic Siúrtáin as her surname.
Irish: Mag, Irish: Nig, and Irish: Mhig are sometimes used instead of Irish: Mac, Irish: Nic, and Irish: Mhic before a vowel or (which is silent) followed by a vowel.
Norman surnames formed by Irish: de (always lowercase; "of") followed by a name, e.g. Irish: de Búrca (Burke), Irish: de Paor (Power), or Irish: de hÍde (Hide, Hyde).
Some names consist of Irish: Mac Giolla ("servant's son") or Irish: Ó Maoil ("follower's descendent") followed by a name in the genitive case, e.g. Irish: Mac Giolla Phádraig, Irish: Ó Maoil Eoin.
| Irish | Anglicisation | Example | |||||
|---|---|---|---|---|---|---|---|
| Base | Person | Case | Meaning | ||||
| nom. | gen./voc. | ||||||
| Ó | Man | Ó | Uí | descendent | O' or omitted | Pól Ó Murchú | |
| Wife | [Bean] Uí | Bhean Uí | descendent's [wife] | Mairéad [Bean] Uí Mhurchú | |||
| Woman | Ní | descendent's daughter | Gráinne Ní Mhurchú | ||||
| Mac | Man | Mac | Mhic | son | Mc, Mac, M', Mag, or omitted | Seán Mac Mathúna | |
| Wife | [Bean] Mhic | Bhean Mhic | son's [wife] | Máire [Bean] Mhic Mhathúna | |||
| Woman | Nic | son's daughter | Aoife Nic Mhathúna | ||||
| de | All | de | of | de or omitted | Séamus de Búrca | ||
Many Irish people use English (or anglicised) forms of their names in English-language contexts and Irish forms in Irish-language contexts. The Irish names of some famous people include:
| English/Anglicised name | Irish name | class=unsortable | Notes |
|---|---|---|---|
| Thomas Ashe | Tomás Ághas | Gaelic League member | |
| Moya Brennan | Máire Ní Bhraonáin[1] | Irish-language spelling as birth name | |
| Turlough O'Carolan | Toirdhealbhach Ó Cearbhalláin | Irish harpist and composer | |
| Michael Collins | Mícheál Ó Coileáin | signed Anglo-Irish Treaty with Irish-language name | |
| Patrick S. Dinneen | Pádraig Ua Duinnín | was an Irish lexicographer and historian, and a leading figure in the Gaelic revival | |
| Enya (Enya Patricia Brennan) | Eithne Pádraigín Ní Bhraonáin | Irish singer, songwriter and musician | |
| Arthur Griffith | Art Ó Gríobhtha | Gaelic League member; Sinn Féin founder and leader; bilingual signature on Anglo-Irish Treaty | |
| Michael D. Higgins | Micheál Ó hUigínn | 9th President of Ireland | |
| Douglas Hyde | Dubhghlas de hÍde | 1st President of Ireland; CnaG founder | |
| Mary McAleese | Máire Mhic Ghiolla Íosa | née Mary Leneghan/Máire Ní Lionnacháin | |
| Liam Mellows | Liam Ó Maoilíosa | ||
| Kevin O'Higgins | Caoimhín Ó hUiginn[2] | Minister for Justice and Vice-President | |
| Seán T. O'Kelly | Seán T. Ó Ceallaigh[3] | Vice-President, first Tánaiste, President of Ireland | |
| Thomas Francis O'Rahilly | Tomás Phroinsias Ó Rathaille[4] | scholar of Celtic language and culture; sometimes also "Rahilly" or "Rahily" | |
| Patrick Pearse | Pádraig Mac Piarais | CnaG
| |
| Joseph Plunkett | Seosamh Máire Pluincéad | Gaelic League member; an Easter Rising leader | |
| Mary Robinson | Máire Bean Mhic Róibín | (née Máire de Búrca) | |
| Gerard Toal | Gearóid Ó Tuathail[5] |
| Irish name | English/Anglicised form | class=unsortable | Notes |
|---|---|---|---|
| Dubhaltach Mac Fhirbhisigh | Dudley Forbes | though neither Dubhaltach or Fibrisigh correspond to the Anglicised forms | |
| Ruaidhrí Ó Flaithbheartaigh | Roderick O'Flaherty | ||
| Flaithrí Ó Maolconaire | Florence Conry | (1560 - 1629, Archbishop of Tuam) | |
| Gráinne Ní Mháille | Grace O'Malley | many other Irish-language and English-language respellings of her name also exist | |
| Seán Bán Breathnach | "White" John Walsh | ||
| Séamus Ó Grianna | James Greene | though Grianna does not correspond etymologically to the English name "Green" or "Greene" | |
| Gráinne Seoige | Grace Joyce | ||
| Eiléan Ní Chuilleanáin | Ellen Cullen | ||
| Antoine Ó Raifteiri | Anthony Raftery | ||
| Proinsias De Rossa | Frank Ross | ||
| Pádraig Harrington | Patrick Harrington | Golfer; three-time major winner | |
| Pádraig Ó Riain | Patrick Ryan | ||
| Pádraig Ó Siochfhradha | Patrick O'Sugrue | ||
| Padraig Ó Síocháin | P. A. Sheehan | ||
| Pádraig Ó Fiannachta | Patrick Finnerty | ||
| Lorcán Ua Tuathail | Laurence O'Toole | ||
| Dara Ó Briain | Darragh O'Brien | ||
| Doireann Ní Bhriain | Doreen O'Brien | ||
| Cathal Brugha | Charles William St. John Burgess | ||
| Éamon de Valera | Edward De Valera | 2nd Taoiseach (1937–1948, 1951–1954, 1957–1959); 3rd President (1959–1973) | |
| Mairéad Ní Mhaonaigh | Mairead Mooney | "Margaret", another English equivalent of "Mairéad", is rarely used. |