| Name | Meaning | Gender | Origin |
|---|
| Omen | | Male | |
| Onix | | Unisex | |
| Onyx | A gemstone with bands of different colours. | Male | |
| Oreo | American cookie brand consisting of two chocolate wafers with white cream filling. | Male | |
| Oreo | American cookie brand consisting of two chocolate wafers with white cream filling. | Male | |
| Orion | Son of Fire
| Male | Greek |
| Oscar | God's spear.
| Male | English |
| Ostara | | Unisex | |
| Othelo | | Unisex | |
| Ozzy | From Osbert - Divinely bright warrior. | Male | |
| Pagan | from the country, countryman | Male | English |
| Pandora | talented one | Female | Greek |
| Panther | A black leopard | Male | |
| Patches | | Male | |
| Penguin | | Male | |
| Pepper | A spice or condiment. | Male | Sanskrit |
| Pepsi | Brand of cola soft drink. | Male | |
| Persephone | The daughter of Demeter and Zeus who was abducted by Hades but rescued by her mother and thereafter spent six months of the year on earth and six months in the underworld.
| Female | Greek |
| Peter | A rock. Peter the biblical fisherman and apostle had impulsive nature and rocklike faith. In Catholic tradition he is the first pope.
| Male | Greek |
| Phantom | Something elusive. A ghost | Unisex | |
| Pharoah | | Unisex | Hebrew |
| Pierre | A rock. Form of Peter.
| Male | |
| Piewacket | | Unisex | |
| Pigment | | Unisex | Hebrew |
| Pinky | For Pinky Lee, the painting, and the color of her nose | Unisex | |