Abbreviations:
| < | from |
| dim. | diminutive |
| OI | Old Irish |
| MI | Middle Irish |
Note: Many of the Irish names are equivalents of the English by tradition and convention, not by any linguistic connection. For example, Donncha is the usual equivalent of Den(n)is, even though the words have completely unrelated histories. Also, many good Irish names do not appear here because they do not have common English equivalents.
| A | |||
| Aaron | Árón | < Hebrew | |
| Adam | Ádam, | < English < Hebrew | |
| Ádhamh | < Biblical form < Hebrew | ||
| Aidan | Aodhán | < OI áedán, dim. of áed (fire) | |
| Alan | Ailín | < Anglo-Norman? | |
| Albert | Ailbhe | < OI Ailbe | |
| Alexander | Alastar | < MI Alusdar < Greek | |
| Andrew | Aindriú, Aindrias | < English < Biblical form | |
| Angus | Aonas, Aonghas | < OI Óengus (“the young god”) | |
| Anthony | Antaine | < Anglo-Norman | |
| Archibald | Giolla Easpaig | < OI Gilla Epscoip (bishop’s servant) | |
| Arnold | Ardal | < OI Artgal (bear-fury) | |
| Art | Art | < OI Art (bear) | |
| Arthur | Artúr | < Anglo-Norman | |
| B | |||
| Barry | Barra | < pet form of OI Barrfind (fair-haired) | |
| Bartley | Beairtle | < OI Parthalán < Latin Bartholomaeus | |
| Bartholomew | Parthalán | < see above | |
| Benedict | Beinidict | < Latin | |
| Benjamin | Beiniaimín | < Hebrew | |
| Bernard | Bearnard | < English | |
| Brendan | Breandán | < OI Brénainn < Welsh Brenhin (prince) | |
| Brian | Brian | < Celtic *brigonos (high, noble?) | |
| C | |||
| Charles | Séarlas, Cathal | < Anglo-Norman < OI Cathal (strong in battle) | |
| Christian | Giolla Chríost | < OI Gilla Críst (Christ’s servant) | |
| Christopher | Críostóir | < Anglo-Norman | |
| Colin | Coilín | < OI Cuilén (whelp, pup, young warrior) | |
| Colm | Colm | < Latin Columba (dove) | |
| Connor | Conchúr, | ||
| Conchubhar | < OI Conchobar (hound-lover) | ||
| Cormac | Cormac | < OI Cormacc (son of defiler??) | |
| D | |||
| Daniel | Dainéil, | < Biblical form <Hebrew | |
| Dónall, Domhnall | < OI Domnall (world-mighty) | ||
| David | Dáithí, Dáibhí | < Hebrew | |
| Declan | Déaglán | < OI Declán | |
| Den(n)is | Donncha, Donnchadh | < OI Donnchad < donn (lord; brown) | |
| Dermot | Diarmaid | < OI Diarmait | |
| Desmond | Deasún | < MI Desmumnach (man from South Munster) | |
| Dominic | Doiminic | < Latin | |
| Donald | Dónall | < OI Domnall (world-might) | |
| Donovan | Donnabhán | < OI Donndubán (dark brown person) | |
| Douglas | Dubhghlas | < OI dubglas (dark green) | |
| Duncan | Donncha, Donnchadh | < OI Donnchad < donn (lord; brown) | |
| E | |||
| Edmund | Éamann | < Anglo-Norman | |
| Edward | Éadbhard | < English | |
| Egan | Aogán | < OI Áeducán, dim. of áed (fire) | |
| Emmet | Eiméid | < English | |
| Enda | Éanna | < OI Énnae (bird-like?) | |
| Ernest | Earnán | < OI Ernán (< iarn “iron”?) | |
| Eugene | Eoghan | < OI Eógan (yew-born) | |
| Euston | Úistean | < Anglo-Norman? | |
| F | |||
| Falvy | Fáilbhe | < OI Fáilbe (wolf-slayer, or, lively) | |
| Felim | Féilim | < OI Fedelmid | |
| Ferdinand | Feardorcha | < OI Ferdorcha (dark man) | |
| Fergus | Fearghas | < OI Fergus (man-strength) | |
| Festus | Fachtna | < OI Fachtna (hostile, malicious) | |
| Finbar | Fionnbhar | < OI Finnbarr (fair-topped, fair-haired) | |
| Finn | Fionn | < OI Finn (fair, bright, white, blond) | |
| Fintan | Fiontán | < OI Fintan (white fire?) | |
| Flann | Flann | < OI Flann (blood red) | |
| Francis | Proinsias | < English | |
| Frank | Frainc | < English | |
| Frederick | Feardorcha | < OI Ferdorcha (dark man) | |
| G | |||
| Garrett | Gearóid | < Anglo-Norman | |
| Geoffrey | Séafra, Seathrún | < Anglo-Norman | |
| George | Seoirse | < Anglo-Norman | |
| Gerald | Gearalt | < Anglo-Norman | |
| Gilbert | Gilbeirt, Giolla Bhríde | < English < OI Gilla Brigde (Brigit’s servant) | |
| Gordon | Gordan | < English | |
| Gregory | Gréagóir | < Anglo-Norman | |
| H | |||
| Harold | Aralt | < Anglo-Norman | |
| Henry | Anraí | < Anglo-Norman | |
| Hugh | Aodh | < OI (fire) | |
| I | |||
| Ian | Eoin | < OI Eoin < Latin Ioannes | |
| Isaac | Íosóg, | < Hebrew < Biblical form, < Hebrew | |
| Ivor | Íomhar | < OI ímar < Old Norse Ívarr | |
| J | |||
| Jacob | Iacób | < Hebrew | |
| James | Séamas | < Anglo-Norman | |
| Jamie | Séimí | < English | |
| Jeffrey | Séafra, Seathrún | < Anglo-Norman | |
| Jeremiah | Irimia, Diarmaid | < Biblical form, < Hebrew < OI Diarmait | |
| Jerry | Diarmaid | < OI Diarmait | |
| Joel | Ióéil | < Biblical form, < Hebrew | |
| John | Seán | < Anglo-Norman Jehan | |
| Joseph | Seosamh, Iosaef | < Hebrew < Biblical form, < Hebrew | |
| Joshua | Iósua | < Hebrew | |
| Jude | Iúd | < Hebrew | |
| Julius | Iúil | < Latin | |
| Justin | Saorbhreathach | < OI Sáerbrethach (of noble judgment) | |
| K | |||
| Kenneth | Cainneach, Coinneach | < OI Cainnech | |
| Kevin | Caoimhín | < OI Cáemgen (beautiful birth) | |
| Kieran | Ciarán | < OI Ciarán (little-dark) | |
| L | |||
| Laughlin | Lochlainn | < MI Lochlainn (Viking?) | |
| Lawrence | Labhrás | < Anglo-Norman | |
| Leo | Leon | < Latin | |
| Leonard | Lionard | < English | |
| Lorcan | Lorcán | < OI Lorccán (< lorcc “silent”, “fierce”) | |
| Louis | Lughaidh | < OI Lugaid (< Lug, the god) | |
| Luke | Lúcás | < Hebrew | |
| M | |||
| Malcolm | Maolcholaim | < OI Máel Coluim (devotee of Colum) | |
| Mark | Marcas | < Hebrew | |
| Martin | Máirtín | < Anglo-Norman | |
| Mat | Mait | < English < Hebrew | |
| Matthew | Maitiú, Matha | < English < Hebrew < Biblical form, < Hebrew | |
| Maurice | Muiris | < OI Muirgius (sea-strength) | |
| Michael | Mícheál | < Anglo-Norman | |
| Mickey | Micí | < English | |
| Mike | Maidhc | < English | |
| Myles | Maolmhuire | < OI Máel Muire (devotee of Mary) | |
| Morgan | Murcha, Murchadh | < OI Murchad (sea-battler) | |
| Murr(a)y | Muiríoch, Muirí | < OI Muiredach (lord, master?) | |
| N | |||
| Nathan | Nátán | < Hebrew | |
| Nathaniel | Natanael | < Hebrew | |
| Neil | Niall | < OI Niall | |
| Nicholas | Nioclás | < Anglo-Norman | |
| Nicol | Niocal | < English | |
| Noel | Nollaig | < Latin | |
| O | |||
| Oliver | Oilibhéar | < English | |
| Oscar | Oscar | < OI Oscar (deer-lover?) | |
| Owen | Eoghan | < OI Eógan (yew-born) | |
| P | |||
| Paddy | Páidín | < dim. of Pádraig | |
| Patrick | Pádraig | < Latin | |
| Paul | Pól | < Latin | |
| Peter | Peadar | < Hebrew | |
| Philip | Pilib | < Hebrew | |
| Pierce | Piaras | < Anglo-Norman | |
| Q | |||
| Quintin | Cúmhaí | < OI Cú Maige (hound of the plain) | |
| R | |||
| Randal | Ránall, Raghnall | < MI Ragnall < Old Norse | |
| Raymond | Réamann | < Anglo-Norman | |
| Richard | Risteard, Risteárd | < Anglo-Norman | |
| Robert | Roibeard, Riobárd | < Anglo-Norman | |
| Roddy | Ruairí, Ruaidhrí | < OI Ruaidrí (great king, or, red king) | |
| Roderick | Ruairí, Ruaidhrí | < see above | |
| Ronald | Ránall, Raghnall | < see Randal | |
| Rory | Ruairí, Ruaidhrí | < see Roderick | |
| S | |||
| Samuel | Samúéil, Somhairle | < Biblical form, < Hebrew < Old Norse Summarliethi (summer farer) | |
| Saul | Sól | < Hebrew | |
| Shay | Sé, Séaghdha | < OI Ségdae (hawklike?) | |
| Simon | Síomón | < Hebrew | |
| Soloman | Solamh | < Hebrew | |
| Sorley | Somhairle | < see Samuel | |
| Stephen | Stiofán | < Anglo-Norman | |
| T | |||
| Terrence | Toirealach, Tárlach, Traolach | < OI Tairdelbach (instigator, abettor) | |
| Theodore | Téadóir | < Anglo-Norman, English | |
| Thomas | Tomás | < Anglo-Norman, English | |
| Timothy | Tiomóid, Tadhg | < Biblical form, < Hebrew < OI Tadc (poet) | |
| Tim | Tadhg | < see above | |
| Turlough | Toirealach, Tárlach, Traolach | < OI Tairdelbach (instigator, abettor) | |
| W | |||
| Walter | Ualtar | < Anglo-Norman, English | |
| William | Uilliam, Liam | < Anglo-Norman, English |