| Ortrun | | AWRT-roon | German | |
| Ortwin | | AWRT-veen (German) | German, Ancient Germanic | |
| Oskar | | AWS-kahr (German, Polish) | Swedish, Norwegian, Danish, German, Polish | |
| Oswald | | AHZ-wawld (English), AWS-vahlt (German) | English, German, Anglo-Saxon | |
| Othmar | | - | German, Czech, Ancient Germanic | |
| Otmar | | - | German, Ancient Germanic | |
| Ottilie | | o-TEE-lee-ə | German | |
| Ottmar | | - | German | |
| Otto | | AW-to (German), AH-to (English), OT-to (Finnish) | German, Swedish, Norwegian, Danish, Dutch, English, Finnish, Ancient Germanic | |
| Ottokar | | - | German | |
| Ottomar | | - | German | |
| Pankraz | | PAHN-krahts | German | |
| Parsifal | | - | German | |
| Pascal | | pas-KAHL (French), pahs-KAHL (Dutch) | French, German, Dutch | |
| Patricia | | pə-TRISH-ə (English), pah-TREE-thyah (Spanish), pah-TREE-syah (Latin American Spanish), pah-TREE-tsee-ah (German) | English, Spanish, German, Late Roman | |