| Name | Meaning | Gender | Origin |
|---|
| Josephine | God will increase | Female | |
| Josette | Jehovah increases | Female | |
| Jovan | Jove-like, majestic | Male | Slavic |
| Joy | From Joyce - Gay and joyful | Female | Word |
| Joyce | after James Augustine Aloysius Joyce, Irish writer and poet | Female | Latin |
| Jules | youthful; soft, downy | Male | |
| Julia | Youthful
| Female | Latin |
| Julie | Youthful: Jove's child. A feminine of Julian.
| Female | |
| Juliet | youthful | Female | English |
| Juliette | youthful | Female | |
| Julius | after Julius Caesar | Male | Latin |
| Kairi | sea | Female | Japanese |
| Kari | curly hair | Male | Norse |
| Klara | Clear, Bright | Unisex | Scandinavian |
| Lace | From Lassy, Normandy | Unisex | English |
| Lacy | Derived from Lacey which is a French Nobleman's surname brought to British Isles after Norman conquest.
| Male | |
| Lafayette | Hound Dog from the AristoCats
| Male | |
| Lamar | land | Male | English |
| Lance | knight's attendant; land | Male | English |
| Lancelot | Knight of Arthur and lover of Guinevere
| Male | |
| Langley | Residence Name | Male | English |
| Latimer | interpreter | Unisex | |
| Launcelot | Knight of Arthur and lover of Guinevere
| Male | |
| Laurel | Laurel
| Female | Latin |
| Lavern | Woodland.
| Female | |