| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 781 | Orpheus | Greek | Son of Apollo. | M | |
| 782 | Orthros | Greek | Guardian of Geryon. | M | |
| 783 | Otis | Greek | Keen of hearing. | M | |
| 784 | Otos | Greek | Keen of hearing. | M | |
| 785 | Otus | Greek | Keen of hearing. | M | |
| 786 | Owain | Greek | Variant of Eugene: Well-born. Famous bearer: Prince Eugene of Savoy; American playwright Eugene O'Neill. | M | |
| 787 | Owen | Greek | Variant of Eugene: Well-born. Famous bearer: Prince Eugene of Savoy. | M | |
| 788 | Palaemon | Greek | A sea god. | M | |
| 789 | Palamedes | Greek | Son of Nauplius. | M | |
| 790 | Pan | Greek | God of flocks. | M | |
| 791 | Panagiotis | Greek | All or holy. | M | |
| 792 | Pancratius | Greek | Supreme ruler. | M | |
| 793 | Pandareos | Greek | A thief. | M | |
| 794 | Pandarus | Greek | Killed for breaking a truce. | M | |
| 795 | Panos | Greek | Rock. | M | |
| 796 | Panteleimon | Greek | Merciful. | M | |
| 797 | Papandrou | Greek | Son of Ander. | M | |
| 798 | Paris | Greek | Son of Priam. | M | |
| 799 | Parthenios | Greek | Virgin. | M | |
| 800 | Patroclus | Greek | Achilles' best friend. | M | |