| Name | Meaning | Region | Gender |
|---|
| Osvaldus | Divine power, Divine ruler | Latin | Boy |
| Oswald | Divine power, Divine ruler | English | Boy |
| Oswald | Power of God | German | Boy |
| Oswallt | Divine power, Divine ruler | Welsh | Boy |
| Osweald | God rule | Anglo-Saxon | Boy |
| Oswin | God friend | Anglo-Saxon | Boy |
| Osya | God will multiply, God will add | Russian | Boy |
| Oszkar | Deer Lover, God's Spear | Hungarian | Boy |
| Ota | Wealthy, Prosperous | Czech & Slovak | Boy |
| Otakar | Watchful of Wealth | Czech & Slovak | Boy |
| Otaktay | Kills many | Native American | Boy |
| Otavio | Eighth | Portuguese | Boy |
| Otes | Wealthy | French | Boy |
| Otetiani | He is prepared | Native American | Boy |
| Otgonbayar | Youngest Joy | Mongolian | Boy |
| Othello | Rich youth | English | Boy |
| Othman | Wealthy | German | Boy |
| Othmann | Wealthy | German | Boy |
| Othniel | Lion of God | English | Boy |
| Otho | Wealthy | German | Boy |
| Othomann | Wealthy | German | Boy |
| Otieno | One who is Born at Night | African | Boy |
| Otilie | Wealthy | Czech & Slovak | Girl |
| Otilie | Fortunate, Heroine, Wealthy | German | Girl |
| Otillie | Little Wealthy One | Czech & Slovak | Girl |
| Otis | Son of Otto | English | Boy |
| Otis | Wealthy | German | Boy |
| Otka | Fortunate, Heroine, Wealthy | German | Girl |
| Otniel | Lion of God | English | Boy |
| Otoahhastis | Tall Bull | Native American | Boy |
| Otoahnacto | Bull Bear | Native American | Boy |
| Otokar | Watchful of Wealth, Happy Warrior | Czech & Slovak | Boy |
| Otso | Bear, Strong | Finnish | Boy |
| Ottah | Third Born | Egyptian | Boy |
| Ottavia | Eighth | Italian | Girl |
| Ottaviano | Eighth | Italian | Boy |
| Ottavio | Eighth | Italian | Boy |
| Otthild | Fortunate, Heroine, Wealthy | German | Girl |
| Otthilda | Fortunate, Heroine, Wealthy | German | Girl |
| Otthilde | Fortunate, Heroine, Wealthy | German | Girl |
| Ottila | Fortunate, Heroine, Wealthy | German | Girl |
| Ottilia | Fortunate, Heroine, Wealthy | German | Girl |
| Ottilie | Fortunate, Heroine, Wealthy | German | Girl |
| Ottis | Son of Otto | English | Boy |
| Otto | Wealth, Fortune | Finnish | Boy |
| Otto | Wealthy, Prosperous | German | Boy |
| Otto | Wealthy | Hungarian | Boy |
| Otto | Wealth, Fortune | Norwegian | Boy |
| Ottokar | Watchful of wealth | German | Boy |
| Ottoline | Wealthy | German | Girl |
| Otylia | Fortunate, Heroine, Wealthy | German | Girl |
| Otylia | Wealthy, Rich | Polish | Girl |
| Oubastet | A Cat | Egyptian | Boy |
| Ouen | Well born | Welsh | Boy |
| Ouida | Famous Warrior | French | Girl |
| Oulam | Eternal, Highland | Hebrew | Boy |
| Oulixes | To be angry, To hate | Greek | Boy |
| Oulixeus | To be angry, To hate | Greek | Boy |
| Ourania | Heavenly | Greek | Girl |
| Ouranos | The Heavens | Greek | Boy |
| Ouray | Arrow | Native American | Boy |
| Ourson | Little Bear | French | Boy |