| Nome | Sginificados | Sexo | Origem |
|---|---|---|---|
| Obelia | pillar of strength | Menina | Greek |
| Oceana | Ocean | Menina | Greek |
| Octavia | the eighth | Menina | Latin |
| Odele | Wealthy | Menina | Greek |
| Odelia | I will praise god | Menina | Hebrew |
| Odera | plough | Menina | Hebrew |
| Odessa | a long journey | Menina | Greek |
| Odetta | Melody | Menina | |
| Olathe | beautiful | Menina | American Indian |
| Olga | Holy | Menina | Scandinavian |
| Oliana | oleander | Menina | Hawaiian |
| Olinda | protector of property | Menina | German |
| Olive | Form of OLIVER. an olive | Menina | Latin |
| Olivia | olive tree | Menina | Greek |
| Olwen | white track (legenday heroine) | Menina | Welsh |
| Olympia | Mountain of the Gods | Menina | Greek |
| Ona | graceful one | Menina | Gaelic |
| Onida | the expected one | Menina | American Indian |
| Oona | One | Menina | |
| Opal | From the Opal Gemstone | Menina | Sanskrit |
| Ophelia | serpent | Menina | Greek |
| Ophira | Gold | Menina | |
| Oprah | Form of OPHIRA. Gold | Menina | Hebrew |
| Ora | Light | Menina | Latin |
| Oralie | golden | Menina | Latin |
| Orenda | magic power | Menina | American Indian |
| Oria | From the Orient | Menina | Greek |
| Oriana | Golden One | Menina | Greek |
| Orianna | golden, dawning | Menina | Latin |
| Oriel | golden, angel of destiny | Menina | French |
| Oriole | fair-haired | Menina | Latin |
| Orla | Golden Woman | Menina | Gaelic |
| Orlantha | from the land | Menina | German |
| Ownah | Form of UNA | Menina |