| Name | Meaning | Gender | Origin |
|---|
| Kitty | Variant of Katherine. Pure.
| Female | English |
| Kitty | Variant of Katherine. Pure.
| Female | English |
| Kitty | Variant of Katherine. Pure.
| Female | English |
| Knickers | | Male | |
| Kreatcher | the Black's house elf
| Male | |
| Lachie | The boy from the Lochs. Warrior.
| Male | |
| Lacy | Derived from Lacey which is a French Nobleman's surname brought to British Isles after Norman conquest.
| Male | |
| Ladybug | | Female | Hebrew |
| Lama | | Male | |
| Lavender Brown | Gryffindor student.
| Female | |
| Lee Jordan | Gryffindor student.
| Male | |
| Lego | | Unisex | |
| Lenny And Squiggy | | Unisex | Hebrew |
| Leo | Lion.
| Male | Latin |
| Licorice | Confection made from the licorice root. | Unisex | |
| Lightweight | | Male | |
| Lilas | | Female | |
| Lillie | Lily | Unisex | English |
| Lily Potter | Harry's mother who was also killed by Lord Voldemort.
| Female | |
| Lisa | Devoted to God
| Female | English |
| Lisa Turpin | Ravenclaw student.
| Female | |
| Lissa | Honey
| Female | African |
| Liz | Hebrew, pledged to God | Female | English |
| Lora | Flower
| Female | |
| Luciano | Form of Luke. Light: illumination.
| Male | Italian |