| Jon (1) | | YOON (Swedish, Norwegian), YON (Danish, Basque) | Swedish, Norwegian, Danish, Basque | |
| Jonas (2) | | YO-nahs (German), JO-nəs (English) | Swedish, Norwegian, Danish, German, Dutch, Biblical | |
| Jonatan | | YO-nah-tahn (German) | Spanish, Swedish, Norwegian, Danish, German | |
| Jonathan | | JAHN-ə-thən (English), YO-nah-tahn (German) | English, German, Swedish, Norwegian, Danish, Dutch, French, Biblical | |
| Jonna | | YON-nah (Finnish) | Danish, Swedish, Finnish | |
| Josef | | YO-zef (German) | German, Swedish, Norwegian, Danish, Czech | |
| Josefina | | ho-se-FEE-nah (Spanish), zhoo-zə-FEE-nə (Portuguese), yoo-se-FEE-nah (Swedish) | Spanish, Portuguese, Swedish | |
| Josefine | | yo-se-FEEN (Swedish), yo-ze-FEE-nə (German) | Swedish, Danish, Norwegian, German | |
| Judit | | YOO-deet (Hungarian) | Hungarian, Spanish, Swedish, Norwegian, Danish | |
| Julia | | JOO-lee-ə (English), YOO-lee-ah (German, Swedish, Danish, Finnish), HOO-lyah (Spanish), YUWL-yah (Polish), YOO-lee-yah (Russian), YOO:-lee-ah (Ancient Roman) | English, German, Swedish, Norwegian, Danish, Dutch, Spanish, Polish, Finnish, Russian, Ukrainian, An | |
| KÅRe | | KOR-e (Swedish) | Norwegian, Swedish, Danish | |
| Kai (1) | | KIE (German, Swedish, Finnish) | Frisian, German, Swedish, Norwegian, Danish, Finnish, Dutch | |
| Kai (2) | | KIE | Swedish | |
| Kaj (1) | | KIE (Swedish) | Swedish, Danish, Norwegian | |
| Kaj (2) | | KIE | Swedish (Rare) | |