| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Caair ny Mart | city | Mayo | Ireland | 53.80 | -9.52 | 380 | 8062 |
| Cabin River | city | Mayo | Ireland | 53.98 | -10.04 | 364 | 854 |
| Cabragh | city | Mayo | Ireland | 53.94 | -9.07 | 85 | 1774 |
| Cahergal | city | Mayo | Ireland | 53.90 | -9.55 | 45 | 1255 |
| Caisleán an Bharraigh | city | Mayo | Ireland | 53.85 | -9.30 | 160 | 13196 |
| Callow | city | Mayo | Ireland | 53.98 | -9.04 | 232 | 1533 |
| Callow | city | Mayo | Ireland | 53.97 | -9.03 | 242 | 1569 |
| Callowbrack | city | Mayo | Ireland | 53.93 | -9.55 | 285 | 1014 |
| Camcloon | city | Mayo | Ireland | 53.90 | -9.54 | 75 | 1350 |
| Camderrynabinnia | city | Mayo | Ireland | 53.84 | -9.08 | 830 | 1819 |
| Camport | city | Mayo | Ireland | 53.92 | -10.02 | 39 | 830 |
| Capnagower | city | Mayo | Ireland | 53.81 | -9.95 | 0 | 113 |
| Cappa | city | Mayo | Ireland | 53.88 | -9.29 | 180 | 11269 |
| Capparanny | city | Mayo | Ireland | 53.89 | -9.19 | 108 | 1934 |
| Cappavicar | city | Mayo | Ireland | 53.86 | -9.21 | 121 | 3257 |
| Cappavicar North | city | Mayo | Ireland | 53.86 | -9.21 | 121 | 3257 |
| Cappavickar | city | Mayo | Ireland | 53.86 | -9.21 | 121 | 3257 |
| Carha | city | Mayo | Ireland | 54.15 | -9.03 | 216 | 1218 |
| Carha | city | Mayo | Ireland | 53.86 | -9.39 | 232 | 1487 |
| Carn | city | Mayo | Ireland | 53.84 | -9.26 | 147 | 10327 |
| Carn | city | Mayo | Ireland | 54.23 | -9.29 | 154 | 1424 |
| Carn | city | Mayo | Ireland | 54.23 | -10.01 | 0 | 1555 |
| Carnhill | city | Mayo | Ireland | 54.27 | -9.80 | 830 | 939 |
| Carracastle | city | Mayo | Ireland | 53.95 | -8.69 | 830 | 1522 |
| Carrick | city | Mayo | Ireland | 53.98 | -9.05 | 246 | 1505 |
| Carrick | city | Mayo | Ireland | 54.24 | -10.02 | 45 | 1579 |
| Carrickaporl | city | Mayo | Ireland | 54.14 | -10.21 | 830 | 89 |
| Carricknaweelion | city | Mayo | Ireland | 54.15 | -10.21 | 830 | 89 |
| Carrigeen | city | Mayo | Ireland | 53.80 | -9.56 | 95 | 6501 |
| Carrigeen Lough | city | Mayo | Ireland | 53.81 | -9.04 | 206 | 2108 |
| Carrigeenmore | city | Mayo | Ireland | 54.08 | -9.86 | 65 | 501 |
| Carroward | city | Mayo | Ireland | 53.88 | -9.08 | 347 | 1676 |
| Carrowbeg | city | Mayo | Ireland | 53.90 | -9.63 | 75 | 491 |
| Carrowbeg | city | Mayo | Ireland | 53.80 | -9.39 | 347 | 1459 |
| Carrowbeg | city | Mayo | Ireland | 53.85 | -9.56 | 49 | 4212 |
| Carrowcally | city | Mayo | Ireland | 53.81 | -9.61 | 0 | 914 |
| Carrowcastle | city | Mayo | Ireland | 53.91 | -9.09 | 150 | 1851 |
| Carrowclogher | city | Mayo | Ireland | 53.79 | -9.29 | 180 | 3362 |
| Carrowcor | city | Mayo | Ireland | 54.31 | -9.32 | 265 | 390 |
| Carrowcuilleen | city | Mayo | Ireland | 54.25 | -9.33 | 282 | 1054 |
| Carrowdrisky | city | Mayo | Ireland | 54.02 | -9.10 | 157 | 1626 |
| Carroweeny | city | Mayo | Ireland | 54.00 | -8.94 | 173 | 1622 |
| Carrower | city | Mayo | Ireland | 54.07 | -9.09 | 183 | 2422 |
| Carrowgarve | city | Mayo | Ireland | 54.02 | -9.21 | 78 | 1584 |
| Carrowgarve | city | Mayo | Ireland | 53.80 | -9.10 | 830 | 1783 |
| Carrowjames | city | Mayo | Ireland | 53.79 | -9.23 | 154 | 2016 |
| Carrowkeel | city | Mayo | Ireland | 53.83 | -9.16 | 252 | 2021 |
| Carrowkeel | city | Mayo | Ireland | 53.90 | -9.19 | 108 | 1810 |
| Carrowkeel | city | Mayo | Ireland | 54.18 | -9.90 | 177 | 857 |
| Carrowkeeran | city | Mayo | Ireland | 53.78 | -9.63 | 239 | 636 |
| Carrowkennedy | city | Mayo | Ireland | 53.70 | -9.55 | 272 | 546 |
| Carrowleagh | city | Mayo | Ireland | 54.14 | -8.99 | 364 | 872 |
| Carrowmore | city | Mayo | Ireland | 54.28 | -9.33 | 830 | 637 |
| Carrowmore | city | Mayo | Ireland | 54.00 | -8.98 | 387 | 1747 |
| Carrowmore | city | Mayo | Ireland | 53.62 | -9.15 | 180 | 1844 |
| Carrowmore | city | Mayo | Ireland | 53.83 | -9.16 | 252 | 1996 |
| Carrowmore | city | Mayo | Ireland | 54.21 | -9.83 | 242 | 896 |
| Carrowmore | city | Mayo | Ireland | 54.25 | -9.28 | 177 | 1353 |
| Carrowmore | city | Mayo | Ireland | 53.77 | -9.24 | 164 | 1485 |
| Carrownaclea | city | Mayo | Ireland | 53.82 | -9.49 | 249 | 7106 |
| Carrownacross | city | Mayo | Ireland | 53.89 | -9.11 | 223 | 1767 |
| Carrownaglogh | city | Mayo | Ireland | 54.12 | -8.98 | 830 | 855 |
| Carrownaglogh | city | Mayo | Ireland | 54.32 | -9.81 | 830 | 453 |
| Carrownahaun | city | Mayo | Ireland | 53.81 | -9.09 | 334 | 1811 |
| Carrownaraha | city | Mayo | Ireland | 53.88 | -9.13 | 249 | 1786 |
| Carrowndangan | city | Mayo | Ireland | 53.82 | -9.06 | 219 | 1845 |
| Carrownteeaun | city | Mayo | Ireland | 53.87 | -9.04 | 272 | 2280 |
| Carrowntleva | city | Mayo | Ireland | 53.86 | -9.08 | 830 | 1699 |
| Carrowntreila | city | Mayo | Ireland | 54.08 | -9.16 | 29 | 10563 |
| Carrownurlaur | city | Mayo | Ireland | 53.85 | -9.25 | 137 | 9144 |
| Carrowteige | city | Mayo | Ireland | 54.31 | -9.81 | 830 | 533 |
| Carrowtober | city | Mayo | Ireland | 53.82 | -9.16 | 265 | 1815 |
| Cartron | city | Mayo | Ireland | 54.13 | -10.09 | 0 | 637 |
| Cartron | city | Mayo | Ireland | 53.82 | -9.15 | 275 | 1920 |
| Cartronduff | city | Mayo | Ireland | 53.86 | -9.41 | 226 | 1292 |
| Cartrongilbert | city | Mayo | Ireland | 54.09 | -10.09 | 0 | 516 |
| Cartur Ghilbeirt | city | Mayo | Ireland | 54.09 | -10.09 | 0 | 516 |
| Cashel | city | Mayo | Ireland | 53.79 | -9.40 | 403 | 1527 |
| Cashel | city | Mayo | Ireland | 53.96 | -9.97 | 219 | 1315 |
| Cashel | city | Mayo | Ireland | 53.96 | -9.08 | 367 | 1926 |
| Cashel | city | Mayo | Ireland | 53.91 | -9.17 | 95 | 1673 |
| Castleaffy | city | Mayo | Ireland | 53.83 | -9.60 | 6 | 1022 |
| Castlebar | city | Mayo | Ireland | 53.85 | -9.30 | 160 | 13196 |
| Castlehill | city | Mayo | Ireland | 54.00 | -9.82 | 121 | 208 |
| Castlehill | city | Mayo | Ireland | 54.05 | -9.34 | 78 | 1446 |
| Cathair na Mart | city | Mayo | Ireland | 53.80 | -9.52 | 380 | 8062 |
| Caurans | city | Mayo | Ireland | 53.94 | -9.20 | 98 | 1267 |