| Name | Meaning | Gender | Origin |
|---|
| Jazz | The romantic music
| Male | Word |
| Jedi | Beloved By God | Unisex | Hebrew |
| Jelly | | Unisex | Hebrew |
| Jerome | sacred name | Male | Greek |
| Julius | after Julius Caesar | Male | Latin |
| Jumper | | Male | Hebrew |
| Karsten | Blessed or annointed one. Alternate Spelling: Carsten. Variant of Kristian.
| Male | Spelling |
| Katana | Sword | Unisex | Japanese |
| Keanu | cool breeze over the mountains | Male | Hawaiian |
| Keely | Beautiful | Unisex | Irish |
| Keene | Ancient.
| Male | |
| Kenji | after Michael Kenji Shinoda, from the band Linkin Park | Male | Japanese |
| Kiefer | barrel-maker | Male | |
| Kirk | church | Male | Norse |
| Klondike | | Male | Hebrew |
| Krishna | dark, black | Male | Sanskrit |
| Lambert | Light of land
| Male | |
| Lamont | Man Of Law | Male | Scottish |
| Laszlo | after the character in the movie Real Genius | Male | Hungarian |
| Leander | lion man | Male | Greek |
| Lemon | | Unisex | Hebrew |
| Leonardo | Lion-bold. Leonardo da Vinci is considered by many to be the most brilliant and creative men who ever lived.
| Male | Italian |
| Lestat | | Unisex | Hebrew |
| Lexus | English variation of Alexios, defending men | Male | Greek |
| Licorice | Confection made from the licorice root. | Unisex | |