| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
|---|
| Blachardstown | city | Baile Atha Cliath | Ireland | 53.3880556 | -6.3755556 | 72 | 84894 |
| Black Bridge | city | Tiobraid Arann | Ireland | 52.5538889 | -8.0211111 | 262 | 2860 |
| Black Bridge | city | County Carlow | Ireland | 52.7769444 | -7.0833333 | 580 | 3702 |
| Black Bridge | city | Cill Mhantain | Ireland | 52.8563889 | -6.2825 | 246 | 4585 |
| Black Bull | city | An Mhi | Ireland | 53.4508333 | -6.4788889 | 255 | 10886 |
| Black Cross Roads | city | Corcaigh | Ireland | 51.845 | -8.7011111 | 259 | 5219 |
| Blackboy Bridge | city | County Limerick | Ireland | 52.6155556 | -8.2930556 | 246 | 5467 |
| Blackburn Bridge | city | County Donegal | Ireland | 54.7758333 | -7.8536111 | 498 | 2429 |
| Blackers Bridge | city | Loch Garman | Ireland | 52.5488889 | -6.7227778 | 347 | 4037 |
| Blacklion | city | An Cabhan | Ireland | 54.2927778 | -7.8752778 | 239 | 2645 |
| Blacklion | city | County Carlow | Ireland | 52.75 | -6.6675 | 488 | 4269 |
| Blackpool | city | County Limerick | Ireland | 52.3780556 | -8.5427778 | 344 | 5491 |
| Blackpool | city | Corcaigh | Ireland | 51.9102778 | -8.4713889 | 187 | 5215 |
| Blackrath Gate | city | Cill Dara | Ireland | 53.0377778 | -6.7869444 | 462 | 6163 |
| Blackraw | city | County Monaghan | Ireland | 54.1936111 | -7.0325 | 501 | 3483 |
| Blackrock | city | Corcaigh | Ireland | 51.8969444 | -8.41 | 3 | 5196 |
| Blackrock | city | County Louth | Ireland | 53.95 | -6.3666667 | 0 | 4053 |
| Blackrock | city | Baile Atha Cliath | Ireland | 53.3030556 | -6.1830556 | 26 | 67263 |
| Blackrocks Cross | city | An Cabhan | Ireland | 54.1638889 | -7.7830556 | 646 | 2282 |
| Blacksod | city | Maigh Eo | Ireland | 54.1002778 | -10.0702778 | 0 | 389 |
| Blackstomes Bridge | city | Ciarrai | Ireland | 52.0172222 | -9.88 | 196 | 2389 |
| Blackwater | city | Loch Garman | Ireland | 52.4466667 | -6.3452778 | 137 | 3002 |
| Blackwater Bridge | city | Ciarrai | Ireland | 51.85 | -9.75 | 0 | 1953 |
| Blackwater Bridge | city | Sligeach | Ireland | 54.0941667 | -7.7075 | 246 | 2230 |
| Blackwater Bridge | city | Loch Garman | Ireland | 52.7219444 | -6.3494444 | 429 | 4026 |
| Blackweir Bridge | city | An Clar | Ireland | 52.6669444 | -9.5883333 | 3 | 2172 |
| Blackwood | city | Cill Dara | Ireland | 53.2866667 | -6.8091667 | 305 | 7152 |
| Blainroe | city | Cill Mhantain | Ireland | 52.9380556 | -6.0386111 | 160 | 1889 |
| Blairs Cove | city | Corcaigh | Ireland | 51.6127778 | -9.5394444 | 213 | 4818 |
| Blanchardstown | city | Baile Atha Cliath | Ireland | 53.3880556 | -6.3755556 | 72 | 84894 |
| Blane Bridge | city | County Limerick | Ireland | 52.4933333 | -9.2875 | 406 | 5196 |
| Blarney | city | Corcaigh | Ireland | 51.9333333 | -8.5666667 | 223 | 5209 |
| Bleach Hill | city | | Ireland | 53.25 | -7.9666667 | 180 | 2696 |
| Bleanmore | city | Maigh Eo | Ireland | 53.9502778 | -9.1369444 | 75 | 1807 |
| Blennerville | city | | Ireland | 52.25 | -9.7333333 | 265 | 2329 |
| Blessington | city | Cill Mhantain | Ireland | 53.17 | -6.5325 | 734 | 8847 |
| Blind Town | city | County Donegal | Ireland | 54.9380556 | -7.6675 | 150 | 2237 |
| Bloomfield Cross Roads | city | Corcaigh | Ireland | 52.1383333 | -8.3966667 | 147 | 5184 |
| Blue Ball | city | County Offaly | Ireland | 53.2244444 | -7.6138889 | 255 | 2661 |
| Bluebell | city | Corcaigh | Ireland | 52.0536111 | -8.2577778 | 318 | 5192 |
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