| Name | Meaning | Gender | Origin |
|---|
| Johnson | Son of John
| Male | English |
| Josephine | God will increase | Female | |
| Julia | Youthful
| Female | Latin |
| Julian | Jove's child. Form of Julius and family clan name of several powerful Roman emperors. Biblical Roman centurion Julius saved Paul's life during a hazardous voyage
| Male | English |
| Juliet | youthful | Female | English |
| Juliette | youthful | Female | |
| June | 6Th Month | Female | English |
| Juno | queen of the heavens | Female | Latin |
| Karina | Italian, dear little one | Female | Scandinavian |
| Katarina | pure | Female | Czech |
| Kate | Pure | Female | English |
| Katelyn | pure | Female | Spelling |
| Katherine | Pure. Used since third century A.D. Early Latin forms Katerina and Caterina became Katharine and Catherine. French Cateline and English Catlyn came into wider use during medieval period when variants multiplied.
| Female | Greek |
| Kelly | Lively: aggressive.
| Female | Irish |
| Kincaid | | Unisex | Hebrew |
| Kipling | after Rudyard Kipling, writer | Unisex | |
| Kitty | Variant of Katherine. Pure.
| Female | English |
| Kitty | Variant of Katherine. Pure.
| Female | English |
| Kitty | Variant of Katherine. Pure.
| Female | English |
| Lady | A female title of nobility. | Female | |
| Lafayette | Hound Dog from the AristoCats
| Male | |
| Lana | Attractive | Female | English |
| Laura | bay laurel | Female | Latin |
| Laurel | Laurel
| Female | Latin |
| Lauren | bay laurel | Female | English |