| Jolanta | | yaw-LAHN-tah (Polish) | Polish, Lithuanian | |
| Jonas (1) | | YO-nus | Lithuanian | |
| Jozefa | | YO-ze-faw (Hungarian) | Hungarian, Slovene | |
| Judit | | YOO-deet (Hungarian) | Hungarian, Spanish, Swedish, Norwegian, Danish | |
| Judita | | - | Lithuanian, Czech, Slovak | |
| Juli | | YOO-lee | Hungarian | |
| Julianna | | yuw-lee-AHN-nah (Polish), joo-lee-AHN-ə (English) | Hungarian, Polish, English | |
| Julija | | YOO-lee-yah (Slovene) | Slovene, Croatian, Lithuanian | |
| Juliska | | - | Hungarian | |
| Juozapas | | - | Lithuanian | |
| Juozas | | - | Lithuanian | |
| Jurgis | | - | Lithuanian | |
| Justina | | jus-TEE-nə (English) | English, Slovene, Czech, Lithuanian, Late Roman | |
| Justinas | | - | Lithuanian | |
| KĘStutis | | - | Lithuanian | |