| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| OSIP | O-seep | Russian | ||
| OSIRIS | o-SIE-ris (English) | Egyptian Mythology (Hellenized) | ||
| OSKAR | AWS-kahr (German, Polish) | Swedish, Norwegian, Danish, German, Polish | ||
| OSKARI | OS-kah-ree | Finnish | ||
| OSKARS | - | Latvian | ||
| OSKU | OS-koo | Finnish | ||
| OSMAN | - | Turkish | ||
| OSMOND | AHZ-mənd | English (Rare) | ||
| OSMUND | - | Anglo-Saxon | ||
| OSSIAN | - | Literature | ||
| OSVALD | - | Swedish, Norwegian, Danish | ||
| OSVALDO | - | Spanish, Italian, Portuguese | ||
| OSWALD | AHZ-wawld (English), AWS-vahlt (German) | English, German, Anglo-Saxon | ||
| OSWIN | AHZ-win | English (Rare) | ||
| OSWINE | - | Anglo-Saxon |