| Name | Group | Language of Origin | Languages of Use | Meaning/Translation or Related Words | US 2021 |
| Aidan | Aodh/Aine | Old Irish | English, Scottish, Irish | fire | #286 |
| Ailbhe | Ailbhe | Old Irish | Irish | Words: white | |
| Aine | Aodh/Aine | Old Irish | Irish | fire | |
| Aishling | Aisling | Irish | Irish | dream, vision | |
| Aisling | Aisling | Irish | Irish | dream, vision | |
| Aislinn | Aisling | Irish | Irish | dream, vision | |
| Alana | Alannah | Old Irish | Irish | Words: child | |
| Alanna | Alannah | Old Irish | Irish | Words: child | |
| Alannah | Alannah | Old Irish | Irish | Words: child | |
| Angus | Aonghus | Old Irish | English, Scottish, Irish | Words: one / vigor, strength | |
| Aodh | Aodh/Aine | Old Irish | Scottish, Irish | fire | |
| Aodhagán | Aodh/Aine | Old Irish | Irish | fire | |
| Aodhán | Aodh/Aine | Old Irish | Scottish, Irish | fire | |
| Aoibhe | Aoife | Old Irish | Irish | beauty | |
| Aoibheann | Aoibheann | Old Irish | Irish | maybe beauty | |
| Aoibhín | Aoibheann | Old Irish | English, Irish | maybe beauty | |
| Aoibhinn | Aoibheann | Old Irish | Irish | maybe beauty | |
| Aoife | Aoife | Old Irish | Irish | beauty | |
| Aonghus | Aonghus | Old Irish | English, Scottish, Irish | Words: one / vigor, strength | |
| Bairre | Barry | Old Irish | Irish | Words: white, fair / head | |
| Barry | Barry | Old Irish | English, Irish | Words: white, fair / head | |
| Braden | Braden | Old Irish | English, Irish | descendant of Bradan | #907 |
| Brady | Brady | Old Irish | English, Irish | descendant of Brághadach | #272 |
| Braeden | Braden | Old Irish | English, Irish | descendant of Bradan | |
| Braxton | Braxton | Old English | English, Irish | Bracca's town | #146 |
| Breck | Bryce | Welsh | Irish | speckled | |
| Brenda | Brenda | Old Norse | English, Irish | Words: sword | |
| Brendan | Brendan | Old Irish | English, Irish | maybe prince | #761 |
| Brennan | Brennan | Old Irish | English, Irish | descendant of Braonán | #871 |
| Brian | Brian/Brianna | Celtic | English, Irish | Words: hill | #288 |
| Briana | Brian/Brianna | Celtic | English, Irish | Words: hill | #637 |
| Brianna | Brian/Brianna | Celtic | English, Irish | Words: hill | #184 |
| Bridget | Bridget | Celtic | English, Scottish, Irish | the exalted one | #722 |
| Brigid | Bridget | Celtic | Irish | the exalted one | |
| Brock | Brock | Old English | English, Irish | badger | #772 |
| Brodie | Brody | Old Irish | English, Irish | maybe ditch | #808 |
| Brody | Brody | Old Irish | English, Irish | maybe ditch | #186 |
| Brogan | Brogan | Old Irish | English, Irish | Words: shoe / shoe | |
| Bryant | Bryant | Old Irish | English, Irish | | #794 |
| Bryson | Bryson | English | English, Irish | son of Bryce | #122 |
| Cadhla | Cadhla | Irish | English, Irish | beautiful | |
| Cael | Caol | Old Irish | English, Irish | slender, narrow | |
| Cainneach | Ken/Kenna | Celtic | Irish | the handsome | |
| Caitlin | Katherine | Old Greek | Irish | maybe the pure | |
| Caitriona | Katherine | Old Greek | Scottish, Irish | maybe the pure | |
| Caoimhe | Caoimhe | Old Irish | Scottish, Irish | the handsome | |
| Caoimhin | Kevin | Old Irish | Irish | the beautiful, the gentle | |
| Caol | Caol | Old Irish | English, Irish | slender, narrow | |
| Caolan | Caol | Old Irish | Irish | slender, narrow | |
| Carey | Carey | Old Irish | English, Irish | descendant of Ciardha | |
| Carson | Carson/Carson | Old Norse | English, Irish, Scottish | maybe son of Carr | |
| Carson | Carson/Carson | Old Norse | English, Irish, Scottish | maybe son of Carr | #98 |
| Cathal | Cathal | Old Irish | Irish | Words: battle / rule | |
| Cathán | Cathán | Old Irish | Irish | Words: battle | |
| Catriona | Katherine | Old Greek | Scottish, Irish | maybe the pure | |
| Ceara | Ceara | Old Irish | English, Irish | bright red | |
| Cera | Ceara | Old Irish | English, Irish | bright red | |
| Cian | Cian | Old Irish | English, Irish | ancient | |
| Cianán | Cian | Old Irish | Irish | ancient | |
| Ciara | Kieran/Ciara | Old Irish | Irish | the black | |
| Ciaran | Kieran/Ciara | Old Irish | Irish | the black | |
| Cillian | Cillian | Old Irish | French, Irish | maybe war, strife | #743 |
| Cionaodh | Cináed | Old Irish | Irish | born of fire | |
| Clodagh | Clodagh | Old Irish | Irish | | |
| Cody | Cody | Old Irish | English, Irish | Words: son | #312 |
| Coleman | Columbano | Latin | English, Irish | dove | |
| Colm | Callum | Latin | Irish | dove | |
| Colman | Columbano | Latin | Irish | dove | |
| Connor | Connor | Old Irish | English, Irish | maybe dog lover | #96 |
| Conor | Connor | Old Irish | English, Irish | maybe dog lover | #462 |
| Cormac | Cormac | Old Irish | Irish | son of the charioteer | |
| Croía | Croía | Irish | Irish | Words: heart | |
| Cuinn | Cuinn | Old Irish | Irish | | |
| Daire | Daire/Dairine | Old Irish | Irish | Words: fruitful, fertile | |
| Dairine | Daire/Dairine | Old Irish | Irish | Words: fruitful, fertile | |
| Daithí | Daithí | Unknown | English, Irish | | |
| Dáithí | Daithí | Unknown | English, Irish | | |
| Dara | Darragh | Old Irish | Irish | oak | |
| Daragh | Darragh | Old Irish | English, Irish | oak | |
| Darina | Daire/Dairine | Old Irish | English, Irish | Words: fruitful, fertile | |
| Darragh | Darragh | Old Irish | English, Irish | oak | |
| Deaglán | Declan | Old Irish | Irish | | |
| Declan | Declan | Old Irish | English, Irish | | #105 |
| Deirdre | Deirdre | Old Irish | English, Irish | maybe sorrowful | |
| Dermod | Diarmaid | Old Irish | English, Irish | freeman | |
| Dermot | Diarmaid | Old Irish | English, Irish | freeman | |
| Desmond | Desmond | Old Irish | English, Irish | from south Munster | #355 |
| Devin | Devin/Devin | Old Irish | English, Irish | the poet | #389 |
| Devin | Devin/Devin | Old Irish | English, Irish | the poet | |
| Diarmaid | Diarmaid | Old Irish | Irish | freeman | |
| Diarmid | Diarmaid | Old Irish | Irish | freeman | |
| Diarmuid | Diarmaid | Old Irish | Irish | freeman | |
| Doireann | Doireann | Old Irish | Irish | | |
| Donagh | Duncan | Old Irish | Irish | brown(haired) warrior | |
| Donal | Donald/Donalda | Celtic | English, Irish | ruler of the world | |
| Donnacha | Duncan | Old Irish | Irish | brown(haired) warrior | |
| Donovan | Donovan | Old Irish | English, Irish | descendant of Donndubhán | #423 |
| Duane | Duane/Duana | Old Irish | English, Irish | the little dark one | |
| Dwayne | Duane/Duana | Old Irish | English, Irish | the little dark one | |
| Éabha | Eve | Hebrew | Irish | live, living, the enlivening | |