| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Sidony | - | English (Archaic) | ||
| Sieffre | - | Welsh | ||
| Siemen | SEE-mən (Dutch) | Dutch, Frisian | ||
| Siemowit | - | Polish (Archaic) | ||
| Siena | see-EN-ə | English (Modern) | ||
| Sienna | see-EN-ə | English (Modern) | ||
| Sierra | see-ER-ə | English (Modern) | ||
| Siet | SEET | Frisian | ||
| Sietse | SEET-sə | Frisian | ||
| Sif | SEEF (Norse Mythology) | Norse Mythology, Danish, Icelandic | ||
| Sigeberht | - | Anglo-Saxon | ||
| Sigeweard | - | Anglo-Saxon | ||
| SigfrØ&Eth;R | - | Ancient Scandinavian | ||
| Sigfrid (1) | SEEG-freed | Swedish | ||
| Sigfrido | seeg-FREE-do (Italian), seeg-FREE-dho (Spanish) | Italian, Spanish |