| Juro (1) | | - | Croatian | |
| Jurriaan | | YUR-ree-ah:n | Dutch | |
| JustÝNa | | - | Czech | |
| Juste | | - | French | |
| Justin | | JUS-tin (English), zhoo-STEN (French) | English, French, Slovene | |
| Justina | | jus-TEE-nə (English) | English, Slovene, Czech, Lithuanian, Late Roman | |
| Justine | | zhuy-STEEN (French), jus-TEEN (English) | French, English, Dutch, German | |
| Justus | | YUWS-tuws (German), JUS-təs (English) | German, Dutch, Late Roman | |
| KÁJa | | - | Czech | |
| KÁRi | | - | Ancient Scandinavian | |
| KÓRi | | - | Ancient Scandinavian | |
| Kader (1) | | - | Arabic | |
| Kagiso | | - | Southern African, Tswana | |
| Kahina | | - | Northern African, Berber | |
| Kai (1) | | KIE (German, Swedish, Finnish) | Frisian, German, Swedish, Norwegian, Danish, Finnish, Dutch | |