| Jaska | | YAHS-kah | Finnish | |
| Jenna | | JEN-ə (English), YEN-nah (Finnish) | English, Finnish | |
| Jenni | | JEN-ee (English), YEN-nee (Finnish) | English, Finnish | |
| Jenny | | JEN-ee (English) | English, Swedish, Finnish, German, Dutch, Spanish | |
| Jere | | YE-re (Finnish), JER-ee (English) | Finnish, English | |
| Jeremias | | ye-re-MEE-ahs (German), YE-re-mee-ahs (Finnish) | German, Portuguese, Finnish | |
| Joakim | | YO-ah-kim (Swedish), YO-ah-keem (Finnish) | Swedish, Norwegian, Danish, Finnish, Serbian, Macedonian | |
| Joel | | JOL (English), JO-əl (English), ho-EL (Spanish), zhoo-EL (Portuguese), YO-el (Swedish, Finnish) | English, Spanish, Portuguese, Swedish, Finnish, Biblical | |
| Johanna | | yo-HAH-nah (German), yo-HAHN-nah (Danish, Dutch), YO-hahn-nah (Finnish) | German, Swedish, Norwegian, Danish, Dutch, Hungarian, Finnish, Estonian, English, Late Roman | |
| Johannes | | yo-HAH-nes (German), yo-HAHN-nəs (Dutch, Danish), YO-hahn-nes (Finnish) | German, Dutch, Swedish, Norwegian, Danish, Finnish, Estonian, Late Roman | |
| Joni (2) | | YO-nee | Finnish | |
| Jonna | | YON-nah (Finnish) | Danish, Swedish, Finnish | |
| Joona | | YO:-nah | Finnish | |
| Joonas | | YO:-nahs | Finnish | |
| Jooseppi | | YO:-sep-pee | Finnish | |