| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Blachardstown | city | Fingal | Ireland | 53.39 | -6.38 | 72 | 106847 |
| Black | city | Ireland | 52.16 | -8.11 | 314 | 1163 | |
| Black Bridge | city | Carlow | Ireland | 52.78 | -7.08 | 830 | 1425 |
| Black Bridge | city | Wicklow | Ireland | 52.86 | -6.28 | 246 | 1958 |
| Black Bridge | city | Ireland | 52.55 | -8.02 | 262 | 1867 | |
| Black Bull | city | Meath | Ireland | 53.45 | -6.48 | 255 | 7634 |
| Black Castle | city | Meath | Ireland | 53.66 | -6.68 | 141 | 19839 |
| Black Cross Roads | city | Cork | Ireland | 51.84 | -8.70 | 259 | 2894 |
| Black Hall Cross | city | Lu | Ireland | 53.78 | -6.30 | 134 | 5542 |
| Black Lion | city | Offaly | Ireland | 53.21 | -7.62 | 269 | 1331 |
| Black Rock | city | Kerry | Ireland | 52.18 | -9.84 | 830 | 1040 |
| Blackboy Bridge | city | Ireland | 52.62 | -8.29 | 246 | 2612 | |
| Blackburn Bridge | city | Donegal | Ireland | 54.78 | -7.85 | 830 | 1878 |
| Blackcastle | city | Meath | Ireland | 53.66 | -6.68 | 141 | 19839 |
| Blackcastle | city | Ireland | 52.45 | -7.84 | 830 | 1457 | |
| Blackcastle Demesne | city | Meath | Ireland | 53.66 | -6.68 | 141 | 19839 |
| Blackcastle House | city | Meath | Ireland | 53.66 | -6.68 | 141 | 19839 |
| Blackcut | city | Meath | Ireland | 53.51 | -6.69 | 252 | 2470 |
| Blackers Bridge | city | Wexford | Ireland | 52.55 | -6.72 | 347 | 1602 |
| Blackfriary | city | Meath | Ireland | 53.56 | -6.79 | 200 | 7776 |
| Blackfriary | city | Meath | Ireland | 53.57 | -6.79 | 223 | 7861 |
| Blackhall | city | Wexford | Ireland | 52.21 | -6.75 | 0 | 1330 |
| Blackhall | city | Wexford | Ireland | 52.37 | -6.62 | 236 | 2525 |
| Blacklion | city | Cavan | Ireland | 54.29 | -7.88 | 239 | 1921 |
| Blacklion | city | Carlow | Ireland | 52.75 | -6.67 | 830 | 1341 |
| Blacklion | city | Wicklow | Ireland | 53.15 | -6.10 | 301 | 36028 |
| Blackpool | city | Cork | Ireland | 51.91 | -8.47 | 187 | 121419 |
| Blackpool | city | Ireland | 52.38 | -8.54 | 344 | 3141 | |
| Blackpool | city | Kerry | Ireland | 52.42 | -9.71 | 337 | 2647 |
| Blackrath Gate | city | Kildare | Ireland | 53.04 | -6.79 | 830 | 2196 |
| Blackraw | city | Monaghan | Ireland | 54.19 | -7.03 | 830 | 3634 |
| Blackrock | city | Lu | Ireland | 53.95 | -6.37 | 0 | 13359 |
| Blackrock | city | Dun Laoghaire-Rathdown | Ireland | 53.30 | -6.18 | 26 | 116093 |
| Blackrock | city | Cork | Ireland | 51.90 | -8.41 | 3 | 70586 |
| Blackrocks Cross | city | Cavan | Ireland | 54.16 | -7.78 | 830 | 768 |
| Blacksod | city | Mayo | Ireland | 54.10 | -10.07 | 0 | 517 |
| Blackstomes Bridge | city | Kerry | Ireland | 52.02 | -9.88 | 196 | 726 |
| Blackwater | city | Wexford | Ireland | 52.45 | -6.35 | 137 | 1645 |
| Blackwater Bridge | city | Kerry | Ireland | 51.85 | -9.75 | 0 | 438 |
| Blackwater Bridge | city | Wexford | Ireland | 52.72 | -6.35 | 830 | 2195 |
| Blackwater Bridge | city | Cavan | Ireland | 54.09 | -7.71 | 246 | 1279 |
| Blackweir Bridge | city | Clare | Ireland | 52.67 | -9.59 | 3 | 1417 |
| Blackwood | city | Kildare | Ireland | 53.29 | -6.81 | 305 | 4508 |
| Blainroe | city | Wicklow | Ireland | 52.94 | -6.04 | 160 | 9989 |
| Blairs Cove | city | Cork | Ireland | 51.61 | -9.54 | 213 | 1138 |
| Blanchardstown | city | Fingal | Ireland | 53.39 | -6.38 | 72 | 106847 |
| Blane Bridge | city | Ireland | 52.49 | -9.29 | 406 | 1661 | |
| Blarney | city | Cork | Ireland | 51.93 | -8.57 | 223 | 17132 |
| Bleach Hill | city | Offaly | Ireland | 53.25 | -7.97 | 180 | 1359 |
| Blean | city | Galway | Ireland | 53.29 | -8.71 | 160 | 3566 |
| Bleankeragh | city | Mayo | Ireland | 54.07 | -9.85 | 213 | 365 |
| Bleanmore | city | Clare | Ireland | 52.65 | -9.35 | 36 | 806 |
| Bleanmore | city | Mayo | Ireland | 53.95 | -9.14 | 75 | 2032 |
| Bleantasour | city | Ireland | 52.21 | -7.66 | 830 | 748 | |
| Blennerville | city | Kerry | Ireland | 52.25 | -9.73 | 265 | 22147 |
| Blessington | city | Wicklow | Ireland | 53.17 | -6.53 | 830 | 3558 |
| Blessington | city | Kilkenny | Ireland | 52.53 | -7.05 | 830 | 1777 |
| Blind Town | city | Donegal | Ireland | 54.94 | -7.67 | 150 | 8417 |
| Blindwood | city | Wicklow | Ireland | 52.87 | -6.17 | 830 | 2090 |
| Bllueford | city | Cork | Ireland | 52.21 | -9.10 | 830 | 1444 |
| Bloomfield Cross Roads | city | Cork | Ireland | 52.14 | -8.40 | 147 | 1550 |
| Bloomsberry | city | Meath | Ireland | 53.71 | -6.80 | 193 | 2569 |
| Blue Ball | city | Offaly | Ireland | 53.22 | -7.61 | 255 | 1557 |
| Bluebell | city | Cork | Ireland | 52.05 | -8.26 | 318 | 1738 |