| Mab | Woman | Irish Names |
| Madadh | Woman | Irish Names |
| Madden | Unisex | Irish Names |
| Madigan | Unisex | Irish Names |
| Maeve | Woman | Irish Names |
| Magee | Man | Irish Names |
| Mahon | Man | Irish Names |
| Mahoney | Unisex | Irish Names |
| Maili | Woman | Irish Names |
| Maire | Woman | Irish Names |
| Mairead | Woman | Irish Names |
| Majella | Woman | Irish Names |
| Malone | Man | Irish Names |
| Maura | Woman | Irish Names |
| Maureen | Woman | Irish Names |
| Mave | Woman | Irish Names |
| McGee | Unisex | Irish Names |
| McKinley | Unisex | Irish Names |
| Meabh | Woman | Irish Names |
| Meara | Woman | Irish Names |