| Name | Meaning | Gender | Origin |
|---|
| Olga | Holy | Female | German |
| Olive | Olive | Female | English |
| Oliver | Elf army | Male | French |
| Opal | Jewel, gem | Female | Sanskrit |
| Ophelia | Help | Female | Greek |
| Orange | Orange | Unisex | English |
| Oreo | American cookie brand consisting of two chocolate wafers with white cream filling. | Unisex | English |
| Orion | Son Of Fire | Male | Greek |
| Orla | Golden princess | Female | Gaelic |
| Orville | Gold town | Male | French |
| Oscar | Divine spear | Male | English |
| Othello | Wealth | Male | German |
| Otis | One who hears well | Male | Greek |
| Otto | Wealth | Male | German |
| Oz | Divine | Male | English |
| Pablo | Small | Male | Latin |
| Pabst | | Unisex | Hebrew |
| Paco | From France | Male | Latin |
| Panda | A bear like Chinese mammal, with distinct black and white markings | Unisex | English |
| Pandora | All gift | Female | Greek |
| Panther | A black leopard | Unisex | English |
| Patches | | Unisex | Hebrew |
| Patience | Patience | Female | English |
| Patrick | Patrician | Male | Latin |
| Patty | A patrician | Female | Latin |
| Paws | | Unisex | Hebrew |
| Peace | Peaceful | Male | English |
| Peaches | Red, yellow skinned fleshy fruit | Unisex | English |
| Peanut | Edible nuts eaten raw or roasted. | Unisex | English |
| Pebbles | After the character in 'The Flintstones' cartoons | Female | English |