| Firstname | Gender | Origin | Meaning of name | Form | Pronunciation |
|---|---|---|---|---|---|
| Octavia |  | Latin | Eighth | Octavius | (ahk TAY vee ah) |
| Olly | | English | Elf army | (AW lee) | |
| Olive | | English | Olive | Olivia | (AW liv) |
| Odessa | | Ukrainian | Place name | (o DEH sah) | |
| Ophelia | | Greek | Help; aid | Itself | (o FEE lee ah) |
| Olivia | | English | Elf army | (o LIV ee ah) | |
| Olympia | | Greek | From Mount Olympus | Itself | (o LYEEM pee ah) |
| Onia | | Hebrew | Ship | Oniya | (O nee yah) |
| Onella | | Greek | Torch; bright light | Ilona | (O nel la) |
| Oneida | | The people of the stone | Itself | (o NIE dah) |
| Firstname | Gender | Origin | Meaning | Form | Pronunciation |
|---|---|---|---|---|---|
| Opal | | Sanskrit | Jewel, gem | Itself | (O pal) |
| Oprah | | Hebrew | Young deer | Ofra | (O pra) |
| Oralee | | Hebrew | My light | (o RA lee) | |
| Ora | | Hebrew | Light | Itself | (O rah) |
| Osanna | | Hebrew | Deliver us | Hosannah | (o ZAN ah) |
| Odalys | | Germanic | Wealth | Odilia | (ODE ah lis) |
| Odetta | | Germanic | Wealth | Odette | (oh DETT ah) |
| Okalani | | Hawaiian | From heaven | Itself | (OH kah la nee) |
| Oka | | Japanese | Cherry blossom | (OH kah) | |
| Olene | | English | N/A | Ole | (oh LEEN) |