| Firstname | Gender | Origin | Meaning of name | Form | Pronunciation |
|---|---|---|---|---|---|
| Oka |  | Japanese | Cherry blossom | (OH kah) | |
| Orianna | | Latin | Dawn, gold | Oriana | (or ee AN nah) |
| Osanna | | Hebrew | Deliver us | Hosannah | (o ZAN ah) |
| Octavia | | Latin | Eighth | Octavius | (ahk TAY vee ah) |
| Olivia | | English | Elf army | (o LIV ee ah) | |
| Olly | | English | Elf army | (AW lee) | |
| Olyvia | | English | Elf army | (oh liv ee uh) | |
| Ouida | | Germanic | Fame and war | (WEE dah) | |
| Orlinda | | Germanic | Famous country | (or LYN da) | |
| Okalani | | Hawaiian | From heaven | Itself | (OH kah la nee) |
| Firstname | Gender | Origin | Meaning | Form | Pronunciation |
|---|---|---|---|---|---|
| Olympia | | Greek | From Mount Olympus | Itself | (o LYEEM pee ah) |
| Osmunda | | English | God, protector | (Os moon dah) | |
| Oralia | | Latin | Golden | Aurelia | (oh RAYL yah) |
| Orla | | Gaelic | Golden princess | (OR lah) | |
| Ophelia | | Greek | Help; aid | Itself | (o FEE lee ah) |
| Olga | | German | Holy | (OL gah) | |
| Opal | | Sanskrit | Jewel, gem | Itself | (O pal) |
| Ora | | Hebrew | Light | Itself | (O rah) |
| Oralee | | Hebrew | My light | (o RA lee) | |
| Olene | | English | N/A | Ole | (oh LEEN) |