| Name | Meaning | Gender | Origin |
|---|
| Olufemi | Beloved Of The Gods | Female | Egyptian |
| Oluwatosin | The Lord Is Worthy To Be Served | Male | English |
| Olwen | Myth Name (Daughter Of Yspaddaden) | Female | Celtic |
| Olwyn | Daughter Of A Giant | Female | Arthurian |
| Olwynn | All White. | Female | Welsh |
| Olya | Unknown | Female | Russian |
| Olympe | From Olympus | Female | French |
| Olympia | From Olympus | Female | Greek |
| Omphale | Myth Name (A Queen Of Lydia) | Female | Greek |
| Onella | Light | Female | Greek |
| Onilee | | Female | English |
| Onille | From The Gold Town | Male | French |
| Onslow | From The Zealous One's Hill | Male | English |
| Onslowe | From The Zealous One's Hill | Male | English |
| Ooljee | Navajo Name Meaning " Moon." | Female | Native American |
| Opal | Jewel PADMA | Female | Indian |
| Ophelia | Serpentine | Female | Greek |
| Ophelie | Serpentine | Female | French |
| Ophelos | Profit; Help | Male | Greek |
| Orabel | Beautiful Seacoast | Female | English |
| Orabelle | Beautiful Seacoast | Female | English |
| Oralee | Light | Female | Hebrew |
| Orali | Light | Female | Hebrew |
| Oralie | Golden | Female | English |
| Ordalf | Elfin Spear | Female | German |
| Ordella | Elfin Spear | Female | German |
| Ordland | From The Pointed Hill | Male | English |
| Ordwald | Spear Strength | Male | English |
| Orelia | Golden | Female | English |
| Orghlaith | Golden | Female | Irish |