| Spartak | | - | Russian, Ukrainian, Bulgarian, Albanian, Armenian, Georgian | |
| Spas | | - | Bulgarian | |
| Stamen | | - | Bulgarian, Macedonian | |
| 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 | |
| Stanka | | - | Slovene, Croatian, Bulgarian | |
| Stanko | | STAHN-ko (Slovene, Croatian) | Slovene, Croatian, Serbian, Bulgarian | |
| Stefan | | SHTE-fahn (German), STAY-fahn (Dutch), STE-fahn (Polish) | German, Swedish, Norwegian, Danish, Dutch, Polish, Bulgarian, Macedonian, Serbian | |
| Stoyan | | - | Bulgarian | |
| Stoyanka | | - | Bulgarian | |
| Svetlana | | svyet-LAH-nah (Russian), sveet-LAH-nah (Russian) | Russian, Slovak, Bulgarian, Serbian, Macedonian | |
| Svetomir | | - | Serbian, Bulgarian | |
| Svetoslav | | - | Bulgarian, Medieval Slavic | |
| Tase | | - | Bulgarian, Macedonian | |