| Juniper | | JOON-ə-pər | English (Rare) | |
| Justice | | JUS-tis | English | |
| 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 | |
| Justy | | JUS-tee | English | |
| Jyoti | | - | Indian, Hindi, Marathi, Bengali, Assamese, Nepali | |
| Kacey | | KAY-see | English (Modern) | |
| Kacie | | KAY-see | English (Modern) | |
| Kade | | KAYD | English (Modern) | |
| Kaden | | KAY-dən | English (Modern) | |
| Kae | | KAY | English (Rare) | |
| Kaeden | | KAY-dən | English (Modern) | |
| Kaelea | | KAY-lee | English (Rare) | |
| Kaelee | | KAY-lee | English (Rare) | |