| Jefimija | | - | Serbian | |
| Jela | | - | Serbian, Croatian, Slovak | |
| Jelena | | - | Serbian, Croatian, Slovene, Estonian, Latvian, Lithuanian | |
| Jelica | | - | Serbian, Croatian | |
| Jelisaveta | | - | Serbian | |
| Jelka | | - | Slovene, Croatian, Serbian | |
| Jevrem | | - | Serbian | |
| Joakim | | YO-ah-kim (Swedish), YO-ah-keem (Finnish) | Swedish, Norwegian, Danish, Finnish, Serbian, Macedonian | |
| Josif | | - | Serbian, Macedonian | |
| Jovan | | - | Serbian, Macedonian | |
| Jovana | | - | Serbian, Macedonian | |
| Jovanka | | - | Serbian, Macedonian | |
| Julijana | | - | Slovene, Croatian, Serbian, Macedonian | |
| Katarina | | kah-tah-REE-nah (German, Swedish) | German, Swedish, Norwegian, Danish, Hungarian, Croatian, Serbian, Slovene | |
| Konstantin | | KAWN-stahn-teen (German), kahn-stahn-TEEN (Russian) | German, Hungarian, Russian, Serbian, Bulgarian, Macedonian | |