| Janja | | - | Croatian, Serbian | |
| Janko | | - | Slovene, Croatian, Serbian, Slovak | |
| Janna | | YAHN-nah (Dutch, Finnish), JAN-ə (English) | Dutch, Swedish, Finnish, English | |
| Janneke | | YAHN-nə-kə | Dutch | |
| Jantine | | yahn-TEE-nə | Dutch | |
| Jantje | | YAHN-tyə | Dutch | |
| Januarius | | - | Ancient Roman | |
| Japheth | | JAY-fəth (English) | Biblical | |
| Jaquan | | - | African American (Modern) | |
| Jarah | | - | Biblical | |
| Jared | | JER-əd (English), JAR-əd (English) | English, Biblical | |
| Jarek | | YAH-rek (Polish) | Polish, Czech | |
| Jareth | | JER-əth (English), JAR-əth (English) | Popular Culture | |
| Jarka | | - | Czech | |
| Jarl | | YAHRL (Norwegian, Swedish, Danish) | Norwegian, Swedish, Danish, Norse Mythology, Ancient Scandinavian | |