| Ondina | A name meaning little wave. |
| Ondreea | A name meaning strong and brave. |
| Ondria | A name meaning courageous woman. |
| Oneekah | A name meaning unique person. |
| Oneesha | A name meaning pure and holy. |
| Oneisha | Ondrea Plus Aisha |
| Onel | A name meaning light of God. |
| Onela | A name meaning bright and sunny. |
| Oneli | A name meaning graceful spirit. |
| Onerva | A name meaning to remember well. |
| Onervo | A Finnish name meaning protector. |
| Onesha | Ondrea Plus Aisha |
| Onesima | A Greek name meaning profitable. |
| Oneyda | People of the Stone |
| Ongkar | A name meaning the only creator. |
| Onia | Our One and Only |
| Onie | Gracious, Merciful |
| Onila | A name meaning the blue colored. |
| Onisha | A name meaning one who is night. |
| Onita | A name meaning one who is light. |
| Onjolee | A name meaning a joyful spirit. |
| Onndrea | A name meaning strong and brave. |
| Onndria | A name meaning a courageous one. |
| Onochie | God is my strength, a Nigerian name meaning divine support |
| Onofledis | Shows her Sword |
| Onoria | A name meaning one of honor. |
| Onorine | A name meaning honorable or noble. |
| Onsiyah | A name meaning a peaceful companion. |
| Ontario | Beautiful place, a Native American name meaning lovely location |
| Onu | A name meaning a leader or a chief. |
| Onukka | A name meaning a gift from the gods. |
| Onya | A name meaning a graceful mountain. |
| Onyka | God is my joy, a Nigerian name meaning divine happiness |
| Ooma | A name meaning a source of wisdom. |
| Oorvasi | To Rise, The Ganges |
| Oota dabun | Gift of the forest, a Native American name meaning woodland treasure |
| Opis | Goddess of Fertility |
| Oportuna | A name meaning timely or lucky. |
| Optimus | Best, a Latin name meaning superior or excellent |
| Opus | Work, a Latin name meaning creation or achievement |