| Name | Meaning | Gender | Origin |
|---|
| Ninja | | Unisex | Hebrew |
| Noah | Rest | Male | Hebrew |
| Oakley | From the oak meadow | Male | English |
| Obsidian | | Unisex | Hebrew |
| Oceana | Ocean | Female | Greek |
| Oleg | Sacred | Male | Russian |
| Olga | Holy | Female | German |
| Olive | Olive | Female | English |
| Oliver | Elf army | Male | French |
| Onyx | A gemstone with bands of different colours. | Unisex | English |
| Opal | Jewel, gem | Female | Sanskrit |
| Oreo | American cookie brand consisting of two chocolate wafers with white cream filling. | Unisex | English |
| Oriel | Bird | Female | English |
| Orion | Son Of Fire | Male | Greek |
| Oscar | Divine spear | Male | English |
| Osiris | Uncertain, perhaps throne of the eye | Unisex | Ancient Egyptian |
| Oswald | Uncertain, possibly divine power | Male | German |
| Othello | Wealth | Male | German |
| Otis | One who hears well | Male | Greek |
| Otto | Wealth | Male | German |
| Owen | Well born, yew born | Male | Gaelic |
| Paddy | Patrician | Male | Latin |
| Paisley | Church, cemetery | Unisex | English |
| Pal | A friend, buddy, chum. | Unisex | English |
| Palmer | Pilgrim | Male | English |
| Pan | Herdsman | Unisex | Greek |
| Pancho | From France | Male | Latin |
| Panda | A bear like Chinese mammal, with distinct black and white markings | Unisex | English |
| Panther | A black leopard | Unisex | English |
| Pasha | Passover | Unisex | Greek |