| Name | Meaning | Gender | Origin |
|---|
| Olive | kind one; olive tree, peace. Symbol of peace. A small oval fruit. | Female | English |
| Oliver | The olive tree. The biblical olive tree symbolizes fruitfulness and beauty and dignity. Extending an olive branch signifies an offer of peace.
| Male | Latin |
| Olivia | Olive
| Female | Latin |
| Ollie | Latin, olive tree | Male | English |
| Olympia | of Mount Olympus, heavenly | Female | Greek |
| 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 | |
| Oscar | God's spear.
| Male | English |
| Otis | Wealthy.
| Male | |
| Otto | Born eighth or wealthy
| Male | |
| Ozzie | Strong
| Male | Short |
| Ozzy | From Osbert - Divinely bright warrior. | Male | |
| Pablo | Little. Form of Paul.
| Male | Spanish |
| Panda | A bear like Chinese mammal, with distinct black and white markings | Male | |
| Pandora | talented one | Female | Greek |
| Patches | | Male | |
| Patrick | Patrician: noble. Romans society was divided into plebeians: (commoners) and patricians: (aristocrats). Saint Patrick - patron saint of Ireland.
| Male | Latin |
| Peach | | Unisex | |
| Peaches | Red, yellow skinned fleshy fruit | Female | English |
| Peaches | Red, yellow skinned fleshy fruit | Female | English |
| Peanut | Edible nuts eaten raw or roasted. | Unisex | |
| Pearl | Precious jewel. A hard, rounded gem, usually white in colour | Female | Latin |
| Pebbles | after the character in 'The Flintstones' cartoons | Male | |
| Penny | Greek, weaver | Female | English |