| Name | Meaning | Gender | Origin |
|---|
| Norbert | blond hero | Male | |
| Obsidian | | Unisex | |
| 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 |
| Onyx | A gemstone with bands of different colours. | Male | |
| Opal | Australian gemstone of remarkable colours, usually red, blue or green | Female | Sanskrit |
| Opal | Australian gemstone of remarkable colours, usually red, blue or green | Female | Sanskrit |
| Opaline | Precious Jewel | Unisex | English |
| Osborn | Soldier of God | Male | English |
| Padme | | Unisex | Hebrew |
| Patty | patrician | Female | English |
| Pearl | Precious jewel. A hard, rounded gem, usually white in colour | Female | Latin |
| Pebbles | after the character in 'The Flintstones' cartoons | Male | |
| Pedro | A Rock | Male | Spanish |
| Peg | pearl | Female | English |
| Peggie | | Unisex | |
| Peggy | pearl | Female | English |
| Penny | Greek, weaver | Female | English |
| Pere | Rock | Unisex | Catalan |
| Perry | French form of Peter
| Male | English |
| Pete | A rock. Form of Peter.
| Male | English |
| 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 |
| Petey | | Male | |
| Petr | Rock | Unisex | Czechoslovakian |
| Petra | rock, stone | Female | Greek |