| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Sea Mount | city | Fingal | Ireland | 53.44 | -6.14 | 3 | 45013 |
| Sea View | city | Cork | Ireland | 51.65 | -8.64 | 85 | 1349 |
| Seacor | city | Donegal | Ireland | 54.94 | -7.90 | 259 | 644 |
| Seafield | city | Fingal | Ireland | 53.47 | -6.18 | 3 | 34865 |
| Seafort | city | Cork | Ireland | 51.51 | -9.59 | 0 | 1323 |
| Sealaclare Bridge | city | Cork | Ireland | 51.56 | -9.41 | 147 | 1208 |
| Seanachadh | city | Mayo | Ireland | 54.24 | -9.93 | 0 | 1417 |
| Seanachaidh | city | Mayo | Ireland | 53.88 | -9.03 | 127 | 2567 |
| Seanadh Fhraochóg | city | Galway | Ireland | 53.28 | -9.21 | 167 | 3148 |
| Seanadh Gharráin | city | Galway | Ireland | 53.28 | -9.30 | 242 | 1505 |
| Seanbhaile Réisc | city | Meath | Ireland | 53.64 | -6.69 | 150 | 18418 |
| Seanchill | city | Dun Laoghaire-Rathdown | Ireland | 53.23 | -6.12 | 6 | 80577 |
| Seanchua | city | Meath | Ireland | 53.54 | -6.93 | 249 | 1992 |
| Seanchua | city | Laois | Ireland | 52.93 | -7.42 | 295 | 1492 |
| Seanghualainn | city | Ireland | 52.57 | -9.10 | 203 | 2204 | |
| Seantrabh | city | Dublin | Ireland | 53.40 | -6.26 | 39 | 224743 |
| Searbhóg | city | Offaly | Ireland | 53.03 | -7.92 | 252 | 2808 |
| Searcóg | city | Cavan | Ireland | 54.00 | -6.90 | 830 | 1867 |
| Seartaglin | city | Kerry | Ireland | 52.18 | -9.40 | 830 | 1739 |
| Sedboro | city | Ireland | 52.91 | -8.31 | 167 | 1341 | |
| Sedenrath | city | Meath | Ireland | 53.73 | -6.83 | 203 | 8067 |
| Seedagh | city | Donegal | Ireland | 55.19 | -7.73 | 0 | 1297 |
| Seerin | city | Offaly | Ireland | 53.09 | -7.91 | 232 | 5454 |
| Seershin | city | Galway | Ireland | 53.27 | -9.22 | 88 | 2435 |
| Seiseadh | city | Clare | Ireland | 53.10 | -9.07 | 223 | 644 |
| Seiseadh Uí Chomáin | city | Sligo | Ireland | 54.08 | -8.81 | 200 | 714 |
| Selbridžas | city | Kildare | Ireland | 53.34 | -6.54 | 173 | 29494 |
| Selloo | city | Monaghan | Ireland | 54.25 | -7.13 | 249 | 2063 |
| Seltanahunshin | city | Leitrim | Ireland | 54.12 | -7.88 | 984 | 405 |
| Seltannaveeny | city | Roscommon | Ireland | 54.10 | -8.12 | 830 | 901 |
| Seltannavenny | city | Roscommon | Ireland | 54.10 | -8.12 | 830 | 901 |
| Seraggeen | city | Ireland | 52.69 | -8.39 | 830 | 1971 | |
| Serothea | city | Ireland | 52.35 | -7.71 | 882 | 16663 | |
| Seskin | city | Ireland | 52.38 | -7.59 | 59 | 1648 | |
| Seskin | city | Wicklow | Ireland | 52.98 | -6.57 | 849 | 739 |
| Seskin Lower | city | Carlow | Ireland | 52.75 | -7.01 | 206 | 2894 |
| Seskin Upper | city | Carlow | Ireland | 52.76 | -7.03 | 830 | 1640 |
| Seskinrea | city | Carlow | Ireland | 52.77 | -7.07 | 830 | 1378 |
| Seskinryan | city | Carlow | Ireland | 52.68 | -6.93 | 377 | 4786 |
| Sessiagh | city | Donegal | Ireland | 55.24 | -7.74 | 82 | 765 |
| Sessuecommon | city | Sligo | Ireland | 54.08 | -8.81 | 200 | 714 |
| Seven Cross Roads | city | Kilkenny | Ireland | 52.80 | -7.29 | 830 | 2234 |
| Seven Houses Cross Roads | city | Kilkenny | Ireland | 52.58 | -7.27 | 229 | 3418 |
| Sevensisters | city | Kilkenny | Ireland | 52.73 | -7.53 | 830 | 2012 |
| Seymourstown Black | city | Meath | Ireland | 53.74 | -7.00 | 830 | 1619 |
| Seymourstown White | city | Meath | Ireland | 53.73 | -6.99 | 416 | 1578 |