| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| OSZKÁR | - | Hungarian | ||
| OTÁVIA | - | Portuguese (Brazilian) | ||
| OTÁVIO | - | Portuguese (Brazilian) | ||
| OTAKAR | - | Czech | ||
| OTAR | - | Georgian | ||
| OTGONBAYAR | - | Mongolian | ||
| OTHELLO | o-THEL-o (English) | Literature | ||
| OTHMAR | - | German, Czech, Ancient Germanic | ||
| OTHNIEL | AWTH-nee-əl (English) | Biblical | ||
| OTHO | - | Ancient Roman | ||
| OTIENO | - | Eastern African, Luo | ||
| OTIS | O-tis | English | ||
| OTMAR | - | German, Ancient Germanic | ||
| OTOKAR | - | Czech | ||
| OTSO | OT-so | Finnish |