| # | ♂ | Name | Meaning |
|---|---|---|---|
| 1 | ♂ | Oliver | Eleven |
| 2 | ♂ | Omar | Life |
| 3 | ♂ | Owen | Young warrior. Also can be a variant of Eugene: Well-born. |
| 4 | ♂ | Onno | The generous |
| 5 | ♂ | Oviel | |
| 6 | ♂ | Ole | What remains of the forefathers |
| 7 | ♂ | Oshmar | |
| 8 | ♂ | Oussama | lion |
| 9 | ♂ | Owemam | |
| 10 | ♂ | Orlando | brave, brave |
| 11 | ♂ | Osvaldo | shapely, clean |
| 12 | ♂ | Otoo | collecting sea shells in a basket |
| 13 | ♀ | Olise | |
| 14 | ♂ | Otugoma | |
| 15 | ♀ | Odeke | |
| 16 | ♂ | Ollie | Diminutive of Oliver: Elf army. Can also be a variant of Olaf: Relic, ancestral heritage. |
| 17 | ♂ | Orpaz | |
| 18 | ♂ | Oswaldo | shapely, clean |
| 19 | ♂ | Oisin | Little |
| 20 | ♂ | Onur | Honor |
| 21 | ♂ | Osmo | |
| 22 | ♂ | Osama | A |
| 23 | ♂ | Orges | |
| 24 | ♂ | Oskar | Spear of the gods |
| 25 | ♂ | Oiva | Superior |
| 26 | ♂ | Ozzy | Diminutive of Oswald: Divine power. |
| 27 | ♂ | Onisimos | |
| 28 | ♂ | Oren | Jerusalem Pine |
| 29 | ♂ | Okke | variant of Germanic |
| 30 | ♂ | Omawnakw | Cloud feather (Hopi). |
| 31 | ♀ | Onyx | a semi-precious stone |
| 32 | ♂ | Olympio | From Mount Olympus |
| 33 | ♂ | Othman | Wealthy. |
| 34 | ♂ | Odd Asbjørn | |
| 35 | ♀ | Origanal | |
| 36 | ♂ | Orrin | The name of an English river. |
| 37 | ♀ | Owen Sparkes | |
| 38 | ♀ | Ona | One. Also a variant of Una: Lamb; together. |
| 39 | ♀ | Olivia | olive tree |
| 40 | ♂ | Otto | Wealth |
| 41 | ♂ | Osman | Godly protection, a combination of the Old Norse words "ass" and "mundr." |
| 42 | ♀ | Oraliz | |
| 43 | ♂ | Onterio | |
| 44 | ♂ | Oriol |