| Silva | | - | Bulgarian, Slovene | |
| Silvester | | sil-VES-tər (English) | Dutch, English, Slovene, Slovak, German, Late Roman | |
| Silvestra | | - | Italian, Slovene | |
| Silvija | | - | Croatian, Slovene | |
| Simon | | SIE-mən (English), see-MAWN (French), ZEE-mawn (German), SEE-mawn (Dutch) | English, French, Swedish, Norwegian, Danish, German, Dutch, Hungarian, Slovene, Romanian, Macedonian | |
| Simona | | - | Italian, Czech, Slovak, Romanian, Lithuanian, Slovene, Bulgarian, Macedonian | |
| Slava | | - | Russian, Slovene, Croatian | |
| Slavica | | - | Serbian, Croatian, Slovene, Macedonian | |
| Slavka | | - | Slovene, Croatian | |
| Slavko | | - | Croatian, Serbian, Slovene | |
| Sonja | | ZAWN-yah (German), SON-yah (Finnish) | German, Dutch, Swedish, Norwegian, Danish, Icelandic, Finnish, Slovene, Serbian, Croatian, Macedonia | |
| SreČKo | | - | Slovene | |
| StaŠA | | - | Serbian, Slovene, Croatian | |
| Stane | | - | Slovene | |
| Stanislav | | stah-nee-SLAHF (Russian) | Czech, Slovak, Russian, Ukrainian, Bulgarian, Slovene, Serbian, Croatian, Medieval Slavic | |