| Name | Meaning | Gender | Origin |
|---|
| Oliver | Elf army | Male | French |
| Olivia | Elf army | Female | English |
| Oreo | American cookie brand consisting of two chocolate wafers with white cream filling. | Unisex | English |
| Otto | Wealth | Male | German |
| Peanut | Edible nuts eaten raw or roasted. | Unisex | English |
| Phoebe | Bright | Female | Greek |
| Pixie | A fairy like creature. Playful and mischievous | Female | English |
| Poppy | Poppy flower | Female | English |
| Princess | Royal son | Female | English |
| Rascal | One that is playfully mischievous | Unisex | English |
| Rei | Salute | Female | Japanese |
| Reiko | Courteous child | Female | Japanese |
| Ren | Water lily | Female | Japanese |
| Rex | King | Male | Latin |
| Riku | Shore | Female | Japanese |
| Rin | Cold | Unisex | Japanese |
| Rina | Pet form of names in -rina | Female | English |
| Ringo | Apple, peace be with you | Male | English |
| Rio | River | Male | Spanish |
| Rocco | Battle cry | Male | Germanic |
| Romeo | Pilgrim to Rome | Male | Italian |
| Rosie | Rose | Female | Latin |
| Roxy | Star | Female | Persian |
| Roz | Weak, tender or soft horse | Female | Germanic |
| Ruby | Red | Female | Latin |
| Rudy | Famous wolf | Male | Germanic |
| Rupert | Bright fame | Male | English |
| Ryo | Fact | Unisex | Japanese |
| Ryoichi | First Son Of Ryo | Male | Japanese |
| Ryoko | Refreshing child | Female | Japanese |