| Name | Meaning | Gender | Origin |
|---|
| Orca | | Unisex | |
| 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 | |
| Oscar | God's spear.
| Male | English |
| Oso | Bear. Oso for males and Osa for females. | Unisex | |
| Otis | Wealthy.
| Male | |
| Owen | Young fighter
| Male | Welsh |
| Ozzie | Strong
| Male | Short |
| Ozzy | From Osbert - Divinely bright warrior. | Male | |
| Pablo | Little. Form of Paul.
| Male | Spanish |
| Palmer | palm bearing pilgrim | Male | English |
| Panther | A black leopard | Male | |
| Pascal | born at Easter | Male | |
| Patch | A pad or shield worn over one eye. | Male | |
| Patches | | Male | |
| Peanut | Edible nuts eaten raw or roasted. | Unisex | |
| Pebbles | after the character in 'The Flintstones' cartoons | Male | |
| Peekaboo | | Male | |
| Pepper | A spice or condiment. | Male | Sanskrit |
| Perry | French form of Peter
| Male | English |
| Petey | | Male | |
| Phantom | Something elusive. A ghost | Unisex | |
| Pheonix | | Unisex | |
| Phineas | oracle; dark-skinned | Male | Hebrew |
| Phoenix | Mystical Bird, Purple
| Male | Greek |