The complete collection contains roughly 10,000 masculine names, so even the most popular name in this list represents only about 2.5% of the total. Needless to say, this selection only represents a small number of the names in the original document, and some "old favorites" will not have made the cut, however it provides a selection of names that were very typical in the early medieval period in Ireland.
In the data below, the first column contains the nominative (regular) form of the name, the second column notes how many different people bore that name in O'Brien's sources, and the third shows one or two typical genitive (possessive) forms of the name (the form that would be used in a patronym, after mac or ua). When more than one spelling is given in either the first or third column, generally one is slightly older than the other. Where the two vary between nd and nn, the nd is older; where they vary between -aich and -aig, the -aich appears to be older (but may simply be a variant). Spelling was not fixed at the time of these documents, and there are spelling variants included in the originals that I have not listed here, rather I have stuck to the most common or "regular" forms, but always ones found in the original documents. The use of hyphens in names like máel-dúin is a modern editorial convention and does not represent historic practice.
In the first section, the names are organized in
order of descending popularity, in the second, they
are alphabetical.
Ordered By Popularity
| Name | Count | Genitive |
|---|---|---|
| Note: The genitive form of a name is the possessive form, like John's in English. It is not simply an alternate spelling of the name. | ||
| Áed | 248 | Áeda |
| Óengus, Áengus | 191 | Óengusa, Áengusa |
| Ailill | 145 | Ailella |
| Fergus | 140 | Fergusa |
| Eochaid | 130 | Echuid, Eochada |
| Lugaid | 129 | Lugdach |
| Domnall | 120 | Domnaill |
| Cairpre | 109 | Cairpri |
| Conall | 108 | Conaill |
| Cormac | 105 | Cormaic |
| Fland, Flann | 96 | Flaind, Flainn |
| Muiredach | 93 | Muiredaich, Muridaig, Muiredaig |
| Cellach | 93 | Cellaich, Celaig |
| Éogan | 87 | Éogain |
| Eochu | 85 | Echach |
| Diarmait | 78 | Diarmata |
| Colmán | 74 | Colmáin |
| Conchobor | 69 | Conchobuir, Conchobair |
| Fiachra | 64 | Fiachrach |
| Énnae | 59 | Énnai |
| Cináed | 58 | Cináeda |
| Crimthann | 58 | Crimthaind, Crimthainn |
| Fedelmid | 53 | Feidelmid, Feideilmid, Feidlimid |
| Murchad | 53 | Murchada |
| Cathal | 49 | Cathail |
| Donnchad | 48 | Donnchada |
| Máel-dúin | 47 | Máel-duin |
| Rónán | 47 | Rónáin |
| Muirchertach | 46 | Muirchertaig |
| Ercc | 45 | Eircc |
| Maine | 45 | Maine |
| Bran | 44 | Brain |
| Cobthach | 44 | Cobthaich, Cobthaig |
| Niall | 44 | Néill |
| Fogartach | 44 | Fogartaich, Fogartaig |
| Crundmáel | 44 | Crundmaíl, Crunnmaíl |
| Bressal | 43 | Bressail |
| Congal | 43 | Congaile |
| Cenn-fáelad | 42 | Cinn-fáelad |
| Dunchad | 42 | Dúnchda |
| Suibne | 41 | Suibne |
| Faílbe | 41 | Faílbe |
| Fiachu | 41 | Fiachach |
| Móenach | 39 | Móenaig |
| Donngal | 39 | Donngaile |
| Sétnae | 39 | Sétna, Sétnae |
| Scandlán | 38 | Scandláin |
| Dímmae | 37 | Dímmai |
| Senach | 37 | Senaich, Senaig |
| Fáelán | 36 | Fáeláin |
| Tuathal | 35 | Tuathail |
| Cummascach | 35 | Cummascaich, Cummascaig |
| Fiachna | 34 | Fiachnae |
| Artt | 33 | Airt |
| Dúngal | 31 | Dúngaile |
| Congalach | 31 | Congalaich |
| Fergal | 31 | Fergaile |
| Blathmac | 30 | Blaithmeic |
| Dubthach | 30 | Dubthaig |
| Dúnlang | 30 | Dúnlainge, Dúnlaing |
| Corcc | 29 | Cuircc |
| Find | 29 | Find |
| Lóegaire | 29 | Lóegairi, Láegaire |
| Feradach | 29 | Feradaig |
| Findchad | 29 | Findchada, Finnachta |
| Finán | 28 | Fináin |
| Cernach | 28 | Cernaich, Cernaig |
| Dáire | 28 | Dáire |
| Ruaidrí | 28 | Ruaidrí |
| Fintan | 28 | Fintain |
| Guaire | 27 | Guaire |
| Trian | 27 | Trena, Triain, Treno |
| Tigernach | 27 | Tigernaich, Tigernaig |
| Sechnassach | 27 | Sechnassaich, Sechnassaig |
| Nath-í | 26 | Nath-í |
| Tadc | 26 | Taidc |
| Báetán | 25 | Báetáin |
| Columb | 25 | Coluimb |
| Forannán | 25 | Forannáin |
| Máel-tuili | 25 | Maili-tuile |
| Cillíne | 24 | Cillíni |
| Máel-ruanaid | 24 | Máel-ruanaid |
| Rechtabra | 24 | Rechtabrat |
| Bróccan | 23 | Broccáin |
| Duinechaid | 23 | Duinechda |
| Colcu | 23 | Colgan |
| Amalgaid | 23 | Amalgada |
| Indrechtach | 23 | Indrechtaich, Indrechtaig |
| Condlae, Conlae | 23 | Condlae, Conlae |
| Fothud | 23 | Fothaid |
| Máelodor | 23 | Máeludir |
| Flaithbertach | 22 | Flaithbertaich, Flaithbertaig |
| Imchad | 22 | Imchada |
| Bécc | 21 | Beicce |
| Carthach | 21 | Carthaich, Carthaig |
| Cerball | 20 | Cerbaill |
| Cúán | 20 | Cúáin |
| Tipraite | 20 | Tipraite |
| Cáirthenn | 20 | Cáirthind, Cáirthinn |
Ordered Alphabetically | ||
| Name | Count | Genitive |
| Note: The genitive form of a name is the possessive form, like John's in English. It is not simply an alternate spelling of the name. | ||
| Áed | 248 | Áeda |
| Ailill | 145 | Ailella |
| Amalgaid | 23 | Amalgada |
| Artt | 33 | Airt |
| Báetán | 25 | Báetáin |
| Bécc | 21 | Beicce |
| Blathmac | 30 | Blaithmeic |
| Bran | 44 | Brain |
| Bressal | 43 | Bressail |
| Bróccan | 23 | Broccáin |
| Cairpre | 109 | Cairpri |
| Cáirthenn | 20 | Cáirthind, Cáirthinn |
| Carthach | 21 | Carthaich, Carthaig |
| Cathal | 49 | Cathail |
| Cellach | 93 | Cellaich, Celaig |
| Cenn-fáelad | 42 | Cinn-fáelad |
| Cerball | 20 | Cerbaill |
| Cernach | 28 | Cernaich, Cernaig |
| Cillíne | 24 | Cillíni |
| Cináed | 58 | Cináeda |
| Cobthach | 44 | Cobthaich, Cobthaig |
| Colcu | 23 | Colgan |
| Colmán | 74 | Colmáin |
| Columb | 25 | Coluimb |
| Conall | 108 | Conaill |
| Conchobor | 69 | Conchobuir, Conchobair |
| Condlae, Conlae | 23 | Condlae, Conlae |
| Congal | 43 | Congaile |
| Congalach | 31 | Congalaich |
| Corcc | 29 | Cuircc |
| Cormac | 105 | Cormaic |
| Crimthann | 58 | Crimthaind, Crimthainn |
| Crundmáel | 44 | Crundmaíl, Crunnmaíl |
| Cúán | 20 | Cúáin |
| Cummascach | 35 | Cummascaich, Cummascaig |
| Dáire | 28 | Dáire |
| Diarmait | 78 | Diarmata |
| Dímmae | 37 | Dímmai |
| Domnall | 120 | Domnaill |
| Donnchad | 48 | Donnchada |
| Donngal | 39 | Donngaile |
| Dubthach | 30 | Dubthaig |
| Duinechaid | 23 | Duinechda |
| Dunchad | 42 | Dúnchda |
| Dúngal | 31 | Dúngaile |
| Dúnlang | 30 | Dúnlainge, Dúnlaing |
| Énnae | 59 | Énnai |
| Eochaid | 130 | Echuid, Eochada |
| Eochu | 85 | Echach |
| Éogan | 87 | Éogain |
| Ercc | 45 | Eircc |
| Fáelán | 36 | Fáeláin |
| Faílbe | 41 | Faílbe |
| Fedelmid | 53 | Feidelmid, Feideilmid, Feidlimid |
| Feradach | 29 | Feradaig |
| Fergal | 31 | Fergaile |
| Fergus | 140 | Fergusa |
| Fiachna | 34 | Fiachnae |
| Fiachra | 64 | Fiachrach |
| Fiachu | 41 | Fiachach |
| Finán | 28 | Fináin |
| Find | 29 | Find |
| Findchad | 29 | Findchada, Finnachta |
| Fintan | 28 | Fintain |
| Flaithbertach | 22 | Flaithbertaich, Flaithbertaig |
| Fland, Flann | 96 | Flaind, Flainn |
| Fogartach | 44 | Fogartaich, Fogartaig |
| Forannán | 25 | Forannáin |
| Fothud | 23 | Fothaid |
| Guaire | 27 | Guaire |
| Imchad | 22 | Imchada |
| Indrechtach | 23 | Indrechtaich, Indrechtaig |
| Lóegaire | 29 | Lóegairi, Láegaire |
| Lugaid | 129 | Lugdach |
| Máel-dúin | 47 | Máel-duin |
| Máel-ruanaid | 24 | Máel-ruanaid |
| Máel-tuili | 25 | Maili-tuile |
| Máelodor | 23 | Máeludir |
| Maine | 45 | Maine |
| Móenach | 39 | Móenaig |
| Muirchertach | 46 | Muirchertaig |
| Muiredach | 93 | Muiredaich, Muridaig, Muiredaig |
| Murchad | 53 | Murchada |
| Nath-í | 26 | Nath-í |
| Niall | 44 | Néill |
| Óengus, Áengus | 191 | Óengusa, Áengusa |
| Rechtabra | 24 | Rechtabrat |
| Rónán | 47 | Rónáin |
| Ruaidrí | 28 | Ruaidrí |
| Scandlán | 38 | Scandláin |
| Sechnassach | 27 | Sechnassaich, Sechnassaig |
| Senach | 37 | Senaich, Senaig |
| Sétnae | 39 | Sétna, Sétnae |
| Suibne | 41 | Suibne |
| Tadc | 26 | Taidc |
| Tigernach | 27 | Tigernaich, Tigernaig |
| Tipraite | 20 | Tipraite |
| Trian | 27 | Trena, Triain, Treno |
| Tuathal | 35 | Tuathail |
Formatted and published by Arval Benicoeur