| Name | Meaning | Gender | Origin |
|---|
| Oliver | Elf army | Male | French |
| Oreo | American cookie brand consisting of two chocolate wafers with white cream filling. | Unisex | English |
| Orville | Gold town | Male | French |
| Oscar | Divine spear | Male | English |
| Otis | One who hears well | Male | Greek |
| Paco | From France | Male | Latin |
| Padfoot | | Unisex | Hebrew |
| Peanut | Edible nuts eaten raw or roasted. | Unisex | English |
| Peewee | | Unisex | Hebrew |
| Pickles | Food flavored in a solution of vinegar | Unisex | English |
| Pip | Lover of horses | Unisex | Greek |
| Pipsqueak | | Unisex | Hebrew |
| Poco | Little. | Unisex | English |
| Popcorn | Corn that when heated forms white edible puffs. | Unisex | English |
| Pretzel | Glazed, salted and brittle biscuit in the form of a knot or stick. | Unisex | English |
| Prongs | | Unisex | Hebrew |
| Puddles | | Unisex | Hebrew |
| Pumpkin | Large round fruit with orange skin | Unisex | English |
| Rascal | One that is playfully mischievous | Unisex | English |
| Rex | King | Male | Latin |
| Riley | Rye clearing | Male | English |
| Rockie | | Unisex | Hebrew |
| Rocky | Battle cry | Male | Germanic |
| Rolo | Burmese | Unisex | English |
| Romy | Sea dew | Unisex | Latin |
| Ron | Ruler with counsel | Male | Norse |
| Roxie | Star | Unisex | Persian |
| Rudy | Famous wolf | Male | Germanic |
| Rupert | Bright fame | Male | English |
| Rusty | Rusty, full of rust | Unisex | American English |