| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
|---|
| Tallyvogy | city | County Monaghan | Ireland | 54.2813889 | -7.011111 | 308 | 3476 |
| Tamlat | city | County Monaghan | Ireland | 54.27 | -6.8719444 | 216 | 4861 |
| Tattyboy | city | County Monaghan | Ireland | 54.0230556 | -6.6211111 | 255 | 6161 |
| Tedavnet | city | County Monaghan | Ireland | 54.2963889 | -7.0138889 | 452 | 3473 |
| The Rock | city | County Monaghan | Ireland | 54.2927778 | -7.0958333 | 449 | 3639 |
| Thornford | city | County Monaghan | Ireland | 54.0772222 | -6.6958333 | 469 | 4200 |
| Tirnaneill Cross Roads | city | County Monaghan | Ireland | 54.2866667 | -6.9663889 | 242 | 3476 |
| Tonagh | city | County Monaghan | Ireland | 54.1586111 | -7.0316667 | 465 | 3444 |
| Tonyglassan | city | County Monaghan | Ireland | 54.1191667 | -6.86 | 475 | 3490 |
| Tossy | city | County Monaghan | Ireland | 54.0797222 | -6.8491667 | 501 | 3478 |
| Tullanacrunat | city | County Monaghan | Ireland | 54.0713889 | -6.6741667 | 351 | 4200 |
| Tullycarragh | city | County Monaghan | Ireland | 54.1036111 | -6.8030556 | 498 | 3490 |
| Tullychattina | city | County Monaghan | Ireland | 54.1305556 | -6.6613889 | 501 | 6008 |
| Tullylougherny | city | County Monaghan | Ireland | 53.9511111 | -6.7772222 | 190 | 3505 |
| Tullynageer | city | County Monaghan | Ireland | 54.1825 | -6.7002778 | 606 | 5362 |
| Tullynamalra Cross Roads | city | County Monaghan | Ireland | 54.0572222 | -6.8183333 | 485 | 3494 |
| Tullyvaragh Lower | city | County Monaghan | Ireland | 54.0244444 | -6.7061111 | 298 | 3836 |
| Tullyvin | city | County Monaghan | Ireland | 54.1058333 | -6.7333333 | 456 | 3491 |
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