| Sigur&Eth;R | | - | Ancient Scandinavian, Norse Mythology | |
| Sigur&Eth;Ur | | - | Icelandic | |
| Silas | | SIE-ləs (English) | English, Greek, Biblical, Biblical Latin, Biblical Greek | |
| Silke | | ZIL-kə (German) | German, Dutch | |
| Silouanos | | - | Biblical Greek | |
| Silvanus | | sil-VAY-nəs (English) | Roman Mythology, Ancient Roman, Biblical, Biblical Latin | |
| Silvester | | sil-VES-tər (English) | Dutch, English, Slovene, Slovak, German, Late Roman | |
| Silvestr | | - | Czech | |
| Silvie | | - | Czech | |
| Silvija | | - | Croatian, Slovene | |
| Silvijo | | - | Croatian | |
| Silvio | | SEEL-vyo (Italian), SEEL-byo (Spanish) | Italian, Spanish, Portuguese, Croatian | |
| Simba (1) | | - | Southern African, Shona | |
| Simba (2) | | - | Eastern African, Swahili | |
| Sime | | - | Macedonian | |