| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
|---|
| Saint Catherines | city | County Donegal | Ireland | 54.6241667 | -8.4627778 | 3 | 794 |
| Saint Johnston | city | County Donegal | Ireland | 54.9333333 | -7.45 | 3 | 4363 |
| Saint Johnstown | city | County Donegal | Ireland | 54.9333333 | -7.45 | 3 | 4363 |
| Sallybrook | city | County Donegal | Ireland | 54.9588889 | -7.5691667 | 308 | 1900 |
| Sandfield | city | County Donegal | Ireland | 54.8027778 | -8.4475 | 3 | 1641 |
| Seacor | city | County Donegal | Ireland | 54.9380556 | -7.9016667 | 259 | 2310 |
| Seedagh | city | County Donegal | Ireland | 55.1861111 | -7.7327778 | 0 | 1733 |
| Sessiagh | city | County Donegal | Ireland | 55.24 | -7.7377778 | 82 | 1261 |
| Shallogan | city | County Donegal | Ireland | 54.8366667 | -8.2219444 | 882 | 2314 |
| Shalwy | city | County Donegal | Ireland | 54.6241667 | -8.5313889 | 0 | 817 |
| Shanaghan | city | County Donegal | Ireland | 54.7680556 | -8.45 | 114 | 2062 |
| Shanbally | city | County Donegal | Ireland | 55.1552778 | -7.9766667 | 1194 | 2091 |
| Shannagh | city | County Donegal | Ireland | 54.5927778 | -8.0541667 | 341 | 2298 |
| Shellbrook | city | County Donegal | Ireland | 55.0225 | -7.5833333 | 0 | 1431 |
| Sheskinapoll | city | County Donegal | Ireland | 54.9102778 | -7.5747222 | 751 | 2311 |
| Single Street | city | County Donegal | Ireland | 54.4830556 | -8.2641667 | 3 | 1245 |
| Slievebane | city | County Donegal | Ireland | 55.3691667 | -7.3375 | 68 | 871 |
| Sockar | city | County Donegal | Ireland | 54.9844444 | -7.8377778 | 449 | 2307 |
| Soppog | city | County Donegal | Ireland | 55.0647222 | -7.3211111 | 206 | 10103 |
| Speenoge | city | County Donegal | Ireland | 55.0394444 | -7.4283333 | 249 | 4180 |
| Srath | city | County Donegal | Ireland | 55.1458333 | -7.2872222 | 990 | 2255 |
| Srath an Urlair | city | County Donegal | Ireland | 54.8 | -7.7666667 | 193 | 2315 |
| Srath an Urláir | city | County Donegal | Ireland | 54.8 | -7.7666667 | 193 | 2315 |
| Straboy | city | County Donegal | Ireland | 54.7455556 | -8.6225 | 515 | 2043 |
| Stracashel | city | County Donegal | Ireland | 54.8177778 | -8.1852778 | 498 | 2315 |
| Strahack | city | County Donegal | Ireland | 55.0769444 | -7.4886111 | 29 | 1626 |
| Straid | city | County Donegal | Ireland | 55.265 | -7.4286111 | 173 | 1548 |
| Straleel | city | County Donegal | Ireland | 54.6802778 | -8.6269444 | 328 | 2257 |
| Straleel North | city | County Donegal | Ireland | 54.6902778 | -8.6402778 | 839 | 2257 |
| Stralongford | city | County Donegal | Ireland | 54.8888889 | -7.7511111 | 518 | 2311 |
| Stranabrooey | city | County Donegal | Ireland | 55.0919444 | -8.2666667 | 249 | 1799 |
| Stranagappoge | city | County Donegal | Ireland | 55.1747222 | -7.2372222 | 597 | 2271 |
| Stranagartan | city | County Donegal | Ireland | 54.7336111 | -8.6105556 | 616 | 2043 |
| Stranarva | city | County Donegal | Ireland | 54.9905556 | -8.2622222 | 770 | 2307 |
| Stranorlar | city | County Donegal | Ireland | 54.8 | -7.7666667 | 193 | 2315 |
| Straruddan | city | County Donegal | Ireland | 55.2505556 | -7.1497222 | 82 | 1793 |
| Straths Bridge | city | County Donegal | Ireland | 55.2741667 | -7.3172222 | 131 | 1989 |
| Stravally | city | County Donegal | Ireland | 54.7294444 | -8.5477778 | 498 | 2064 |
| Stream's Town | city | County Donegal | Ireland | 55.1291667 | -7.7166667 | 32 | 1840 |
| Streamʼs Town | city | County Donegal | Ireland | 55.1291667 | -7.7166667 | 32 | 1840 |
| Swillybrin | city | County Donegal | Ireland | 55.1494444 | -7.9488889 | 108 | 1922 |
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