| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Olya | - | Russian | ||
| Olympias | - | Ancient Greek | ||
| Olympiodoros | - | Ancient Greek | ||
| Olympos | - | Ancient Greek | ||
| Om | - | Indian, Hindi, Marathi | ||
| Omid | - | Persian | ||
| Omobolanle | - | Western African, Yoruba | ||
| Omolara | - | Western African, Yoruba | ||
| Ona (1) | - | Lithuanian | ||
| Ona (2) | - | Catalan | ||
| Ondina | - | Portuguese, Italian | ||
| Onesimos | - | Ancient Greek, Biblical Greek | ||
| Onesiphoros | - | Ancient Greek, Biblical Greek | ||
| Oni | - | Western African, Yoruba | ||
| Onisim | - | Russian (Rare) |