| Name | Meaning | Gender | Origin |
|---|
| Oreo | American cookie brand consisting of two chocolate wafers with white cream filling. | Male | |
| Orion | Son of Fire
| Male | Greek |
| Orlando | Famous land
| Male | Italian |
| Oscar | God's spear.
| Male | English |
| Osiris | with strong eyesight | Male | Egyptian |
| Oswald | Divinely powerful
| Male | English |
| Othello | he has the sound of God | Male | Hebrew |
| Other | | Unisex | Hebrew |
| Otis | Wealthy.
| Male | |
| Otto | Born eighth or wealthy
| Male | |
| Outlaw | A rebel or fugitive from the law. | Unisex | |
| Owen | Young fighter
| Male | Welsh |
| Ozzie | Strong
| Male | Short |
| Pacific | tranquil | Male | |
| Pamela | honeyed | Female | English |
| Panama | | Female | Hebrew |
| Panda | A bear like Chinese mammal, with distinct black and white markings | Male | |
| Pandora | talented one | Female | Greek |
| Panther | A black leopard | Male | |
| Panthor | | Unisex | |
| Paprika | Spicy powder made from sweet red peppers. | Unisex | |
| Paquita | Free
| Female | Spanish |
| Passion | Powerful emotions, boundless enthusiasm. | Unisex | |
| Patches | | Male | |
| Pavarotti | | Unisex | |