| Name | Gender | Meaning | Favorites |
| Ornice | Boy | Cedar tree | |
| Oro | Boy | Gold | |
| Orpah | Girl | Fawn | |
| Orpita | Girl | Offering | |
| Orsen | Boy | Bear-Like | |
| Orson | Boy | Little Bear | |
| Orvadasp | Boy | Possessing swift horses | |
| Orville | Boy | Golden city | |
| Orzora | Girl | God's Strength | |
| Osama | Boy | Lion-like | |
| Osanna | Girl | Praise | |
| Oscar | Boy | Spear of God | |
| Oshma | Girl | Summer season | |
| Osho | Boy | Dear | |
| Osias | Boy | Salvation | |
| Osip | Boy | God wiIl multiply | |
| Osiris | Boy | Judge of the dead | |
| Osman | Boy | Tender Youth | |
| Ossama | Boy | One of the names of the lion | |
| Osvaldo | Boy | God power | |
