| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Octavianus | - | Ancient Roman | ||
| Octavio | ok-TAH-vyo | Spanish | ||
| Octavius | ahk-TAYV-ee-əs (English) | Ancient Roman | ||
| Oda | O-dah (German) | German, Ancient Germanic | ||
| Odalis | - | Spanish | ||
| Odalric | - | Ancient Germanic | ||
| Odalys | - | Spanish | ||
| Odarka | - | Ukrainian | ||
| Odd | - | Norwegian | ||
| Oddmund | - | Norwegian | ||
| Oddo | - | Italian | ||
| Oddr | - | Ancient Scandinavian | ||
| Odeta | - | Lithuanian | ||
| Odhiambo | - | Eastern African, Luo | ||
| Odila | - | Ancient Germanic |