| Oldrich | | - | Slovak | |
| Ole | | OL-e (Danish) | Danish, Norwegian | |
| Oleg | | ah-LYEK | Russian | |
| OlegÁRio | | - | Portuguese | |
| Olegario | | - | Spanish | |
| Olek | | AW-lek | Polish | |
| Olev | | - | Estonian | |
| Olga | | OL-gah (Russian), AWL-gah (Polish, German) | Russian, Ukrainian, Polish, German, Swedish, Norwegian, Danish, Icelandic, Latvian, Hungarian, Itali | |
| Olgica | | - | Macedonian, Serbian | |
| Oli | | AHL-ee | English | |
| Olimpia | | aw-LEEM-pyah (Polish) | Italian, Spanish, Romanian, Polish, Hungarian | |
| Olive | | AHL-iv | English | |
| Oliver | | AHL-ə-vər (English), AW-lee-ver (German), O-lee-ver (Finnish) | English, German, Swedish, Norwegian, Danish, Finnish, Estonian, Serbian, Croatian, Macedonian, Czech | |
| Olivera | | - | Serbian, Croatian, Macedonian | |
| Olivia | | ə-LIV-ee-ə (English), o-LEE-vyah (Italian, Spanish), o-LEE-vee-ah (German), O-lee-vee-ah (Finnish) | English, Italian, Spanish, German, Finnish, Swedish, Norwegian, Danish | |