| Tadhg | Man | Irish Names |
| Taisce | Unisex | Irish Names |
| Tara | Woman | Irish Names |
| Tarmon | Man | Irish Names |
| Tavish | Man | Irish Names |
| Teagan | Unisex | Irish Names |
| Teague | Man | Irish Names |
| Teige | Man | Irish Names |
| Tiergan | Man | Irish Names |
| Tierna | Woman | Irish Names |
| Tiernan | Man | Irish Names |
| Tierney | Unisex | Irish Names |
| Tieve | Woman | Irish Names |
| Tigernach | Unisex | Irish Names |
| Tighearnach | Man | Irish Names |
| Torin | Man | Irish Names |
| Torrin | Unisex | Irish Names |
| Tremayne | Unisex | Irish Names |
| Trory | Man | Irish Names |
| Tully | Unisex | Irish Names |