| Sigur&Eth;R | | - | Ancient Scandinavian, Norse Mythology | |
| Sigurd | | SEE-gurd (Swedish) | Norwegian, Danish, Swedish, Norse Mythology | |
| Silvanus | | sil-VAY-nəs (English) | Roman Mythology, Ancient Roman, Biblical, Biblical Latin | |
| Silvia | | SEEL-vyah (Italian), SEEL-byah (Spanish) | Italian, Spanish, Portuguese, Romanian, Slovak, English, German, Late Roman, Roman Mythology | |
| Silvius | | - | Late Roman, Roman Mythology | |
| Sindri | | - | Norse Mythology, Ancient Scandinavian, Icelandic | |
| Sionann | | - | Irish Mythology | |
| Siv | | SEEV | Swedish, Norwegian, Danish, Norse Mythology | |
| Ska&Eth;I | | - | Norse Mythology | |
| Skadi | | - | Norse Mythology | |
| Skuld | | - | Norse Mythology | |
| Sohrab | | - | Persian, Persian Mythology | |
| Soroush | | - | Persian Mythology, Persian | |
| Sosruko | | - | Caucasian Mythology | |
| Sraosha | | - | Persian Mythology | |