| Gael | Unisex | Irish Names |
| Gallagher | Man | Irish Names |
| Galvin | Man | Irish Names |
| Gannon | Man | Irish Names |
| Garvey | Man | Irish Names |
| Gavan | Man | Irish Names |
| Gilmore | Man | Irish Names |
| Gilroy | Man | Irish Names |
| Giolla | Man | Irish Names |
| Gleason | Unisex | Irish Names |
| Grady | Man | Irish Names |
| Gráinne | Woman | Irish Names |
| Grian | Man | Irish Names |