| Name |
Pronunciation |
Meaning |
English Spelling |
Gender |
| Tadc, Tadhg | (TEEG) | a poet | Teague | M |
| Tadgán, Tadhgán | (TEE-gan) | dim. of Tadhg | Teegan | M |
| Tailech, Tuileach | (TAL-ach) | | | M |
| Tailefhlaith, Tuilelaith | (TIL-al-la) | lady of abundance | Talulah | F |
| Tailltiu, Taillte | (TAL-tee) | | Taltey, Taltena | F |
| Tairdelbach, Toirdhealbhach, Traolach, Tárlach | (TREL-ach, TAR-lach) | instigator, abettor | Tarlach, Tarla, Turlough | M |
| Taithlech, Taichleach | (TAL-lach) | pacifying, placating | Talley | M |
| Tanaide, Tanaidhe, Tanaí | (TAWN-ee) | slender, subtle | | M |
| Tassach | (TAS-ach) | perhaps "idle, inactive" | | M |
| Techán, Teachán | (ta-KAWN) | fair | | M |
| Téite, Téide | (TEE-da) | | Teida | F |
| Temair, Teamhair | (TOWR) | eminence | Tara | F |
| Temnén, Teimhnín | (TEV-neen, TAY-neen) | dark | Tynen | M |
| Tethba, Teathbha, Teafa | (TAF-fa) | | Teafa, Teffa | F |
| Tigernach, Tighearnach, Tiarnach | (TEER-nach) | a lord | Tierney | M |
| Tigernán, Tighearnán, Tiarnán | (teer-NAWN) | a lord | Tiernan | M |
| Tipraite, Tiobraide | (tuh-BREED-a) | | Tubridy, Tiobrady | M |
| Tírechán, Tíreachán | (TEER-ach-awn) | possessing much land | Tierachan | M |
| Tóla | (TOH-la) | abundance, flood | | M |
| Tomaltach | (TOM-al-tach) | | Tomelty | M |
| Tomás | (to-MAS) | borrowing of Biblical Thomas | | M |
| Tómma, Tuama | (TOOM-a) | | Twomey, Toomey | M |
| Tómmán | (tom-AWN) | dim of Tómma | | M |
| Tómnat, Tuamnait | (TOOM-nit) | fem. form of Tómmán | | F |
| Torccán, Torcán | (tur-KAWN) | wild boar | | M |
| Torna | (TOR-na) | name of legendary scholar | | M |
| Tressach, Treasach | (TRES-sach) | warlike, fierce | Treasaigh, Tracey | M |
| Tríona | (TREE-na) | short for Caitríona | | F |
| Tuathal | (TOO-a-hal) | ruler of the people | Tully | M |
| Tuathflaith, Tuathlaith, Tuathla | (TOO-la) | princess of the people | | F |