Variant spellings are included, so there may be some duplication. If you know of something that should be included, please let me know
| Tagart |
| Tagart |
| Tagert |
| Tagert |
| Taggart |
| Taggart |
| Taggert |
| Taggert |
| Tague |
| Teage |
| Teague |
| Tegart |
| Tegart |
| Teggart |
| Teggart |
| Teige |
| Teigue |
| Teirnan |
| Ternan |
| Tiernan |
| Tige |
| Tighe |
| Tigue |
| Timblin (archived) |
| Timlin (archived) |
| Tinney |
| Tinney Cavan |
| Tinney (archived) |
| Tinney Ireland, New York (archived) |
| Tinny |
| Tinny Cavan |
| Tinny (archived) |
| Tinny Ireland, New York (archived) |
| Tolster |
| Tomalty (archived) |
| Tomelty (archived) |
| Tomilty (archived) |
| Tomulty (archived) |
| Toomey Listowel to London (archived) |
| Toomy Listowel to London (archived) |
| Tormay |
| Tormey |
| Tormy |
| Torrance Derry |
| Torrence Derry |
| Torrens Derry |
| Toulster |
| Tracey Cappawhite, Co. Tipperary /Franklin Co., NY |
| Tracey Lewis |
| Tracey |
| Tracey Soloheadbeg area, Co. Tipperary |
| Tracy Cappawhite, Co. Tipperary /Franklin Co., NY |
| Tracy Lewis |
| Tracy |
| Tracy Soloheadbeg area, Co. Tipperary |
| Trahy |
| Treacy Cappawhite, Co. Tipperary /Franklin Co., NY |
| Treacy Lewis |
| Treacy |
| Treacy Soloheadbeg area, Co. Tipperary |
| Treahy |
| Treehy |
| Trehey |
| Trehy |
| Trihy |
| Troy |
| Tumalty (archived) |
| Tumbletee (archived) |
| Tumelty (archived) |
| Tumilty (archived) |
| Tummulty (archived) |
| Tumulty (archived) |
| Tuomey Listowel to London (archived) |
| Tuomy Listowel to London (archived) |
| Turmey |
| Twomey Listowel to London (archived) |
| Twomy Listowel to London (archived) |
| Twoomy Listowel to London (archived) |
| Tyghe |