| comment/origin etc. | famous bearer of this name | |
| Oana | ||
| Oceana | ||
| Octavia | ||
| Oda | ||
| Odalberta | ||
| Odalinde | ||
| Odalis | ||
| Oded | ||
| Odette | ||
| Odile | ||
| Odilia | ||
| Odilie | ||
| Odina | ||
| Odine | ||
| Okka | ||
| Ok-Kyo | (corean) | |
| Oksana | ||
| Olga | ||
| Oline | ||
| Olive | ||
| Olivia | ||
| Olympe | ||
| Olympia | ||
| Oodgeroo | (australian) | |
| Oona | ||
| Ophelia | ||
| Oriana | ||
| Oriel | ||
| Ortraud | ||
| Ottilie | ||
| Ottoline | ||
| Ottwine | ||
| Otwine | ||
| Oxana |