| Sigismund | | - | German, Ancient Germanic | |
| Sigivald | | - | Ancient Germanic | |
| Sigiward | | - | Ancient Germanic | |
| Sigmund | | ZEEK-muwnt (German), SIG-mənd (English) | German, Swedish, Norwegian, Danish, English | |
| Sigmundr | | - | Ancient Scandinavian | |
| SignÝ | | - | Ancient Scandinavian, Norse Mythology, Icelandic | |
| SigrÍ&Eth;R | | - | Ancient Scandinavian | |
| SigrÚN | | - | Ancient Scandinavian, Norse Mythology, Icelandic | |
| Sigsteinn | | - | Ancient Scandinavian | |
| Sigur&Eth;R | | - | Ancient Scandinavian, Norse Mythology | |
| Silas | | SIE-ləs (English) | English, Greek, Biblical, Biblical Latin, Biblical Greek | |
| Silva | | - | Bulgarian, Slovene | |
| Silvanus | | sil-VAY-nəs (English) | Roman Mythology, Ancient Roman, Biblical, Biblical Latin | |
| Silver | | SIL-vər | English | |
| Silvester | | sil-VES-tər (English) | Dutch, English, Slovene, Slovak, German, Late Roman | |