| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| SluaghadhÁN | - | Ancient Irish | ||
| Somhairle | - | Scottish, Irish | ||
| Sorcha | SAWR-ə-khə (Irish), SAWR-khə (Irish) | Irish, Scottish | ||
| Sorley | SAWR-lee | Scottish, Irish | ||
| StiofÁN | shtee-FAWN | Irish | ||
| Suibhne | SIV-na (Irish, Scottish) | Irish, Scottish, Ancient Irish | ||
| Suibne | - | Irish | ||
| Sweeney | - | Irish, Scottish |