T
- (County Donegal) Tullybegly
- (County Monaghan) Tattyboy
- (County Monaghan) Tullylougherny
- (An Cabhán) Tonyduff
- (An Cabhán) Tirlahode Lower
- (An Cabhán) Tullycoe
- (An Cabhán) Treehog Cross Roads
- (An Cabhán) Trinity Island
- (An Cabhán) Toberlyan
- (County Donegal) Tober
- (County Monaghan) Tullyvaragh Lower
- (County Donegal) Tullyonven
- (County Donegal) Tullyrap
- (County Donegal) Tops
- (County Donegal) Tirinisk
- (County Donegal) Toberkeen
- (County Donegal) Tieveragh
- (County Donegal) Tievelough
- (County Donegal) Tangaveane
- (County Donegal) Tully Beg
- (County Monaghan) Tullynageer
- (County Monaghan) Tullybryan
- (An Cabhán) Teeboy
- (An Cabhán) Tullynamoyle
- (An Cabhán) Tuam Island
- (County Monaghan) Tallyvogy
- (County Monaghan) Tirnaneill Cross Roads
- (County Monaghan) Tamlat
- (County Monaghan) The Rock
- (County Monaghan) Tonagh