| Sofiya | | sah-FEE-yah (Russian) | Russian, Ukrainian, Bulgarian | |
| Sofya | | - | Russian | |
| Sonya | | SON-yə (English), SAWN-yə (English) | Russian, English | |
| Spartak | | - | Russian, Ukrainian, Bulgarian, Albanian, Armenian, Georgian | |
| Stanimir | | - | Bulgarian, Russian, Serbian, Medieval Slavic | |
| Stanislav | | stah-nee-SLAHF (Russian) | Czech, Slovak, Russian, Ukrainian, Bulgarian, Slovene, Serbian, Croatian, Medieval Slavic | |
| Stanislava | | stah-nee-SLAH-vah (Russian) | Czech, Slovak, Bulgarian, Serbian, Croatian, Slovene, Russian, Medieval Slavic | |
| Stas | | STAHS | Russian | |
| Stasya | | - | Russian | |
| Stepan | | stye-PAHN (Russian), stee-PAHN (Russian) | Russian, Armenian | |
| Susanna | | soo-ZAHN-nah (Italian), SOO-sahn-nah (Finnish), soo-ZAN-ə (English) | Italian, Swedish, Finnish, Russian, Dutch, English, Biblical, Biblical Latin, Old Church Slavic | |
| Sveta | | - | Russian | |
| Svetlana | | svyet-LAH-nah (Russian), sveet-LAH-nah (Russian) | Russian, Slovak, Bulgarian, Serbian, Macedonian | |
| Svyatopolk | | - | Russian | |
| Svyatoslav | | svyah-tah-SLAHF (Russian) | Russian, Ukrainian | |