| Name | Meaning | Gender | Origin |
|---|
| 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 |
| Onyx | A gemstone with bands of different colours. | Male | |
| Orion | Son of Fire
| Male | Greek |
| Orson | Little bear
| Male | Latin |
| Osborn | Soldier of God | Male | English |
| Osiris | with strong eyesight | Male | Egyptian |
| Oswald | Divinely powerful
| Male | English |
| Otis | Wealthy.
| Male | |
| Owen | Young fighter
| Male | Welsh |
| Paco | Eagle
| Male | Spanish |
| Pancho | Nickname for Francisco and Frank.
| Male | Spanish |
| Parker | cultivated land | Male | English |
| Patrick | Patrician: noble. Romans society was divided into plebeians: (commoners) and patricians: (aristocrats). Saint Patrick - patron saint of Ireland.
| Male | Latin |
| Penn | enclosure | Male | English |
| Pepper | A spice or condiment. | Male | Sanskrit |
| Perdy | | Unisex | |
| Peregrine | traveler, pilgrim | Male | Latin |
| Perth | From the thorn bush or thicket
| Male | Scottish |
| Peter | A rock. Peter the biblical fisherman and apostle had impulsive nature and rocklike faith. In Catholic tradition he is the first pope.
| Male | Greek |
| Philip | horse lover | Male | Greek |
| Pierce | rock | Unisex | |
| Pierce | rock | Male | English |
| Plato | broad-shouldered | Male | Greek |
| Pollux | crown | Male | Greek |
| Polo | brave wanderer | Male | Tibetan |