| Name | Meaning | Gender | Origin |
|---|
| Jerk | Ever Powerful Ruler | Unisex | Swedish |
| Jessica | God's grace | Female | Hebrew |
| Jessie | wealthy | Female | Anglicized |
| Jessy | God's Gracious Gift | Unisex | Hebrew |
| Jodie | From Judith - Admired and praised | Unisex | |
| Josh | God Saves | Unisex | English |
| Joyce | after James Augustine Aloysius Joyce, Irish writer and poet | Female | Latin |
| Jr. | | Unisex | Hebrew |
| Judy | Hebrew, He will be praised, woman from Judea | Female | English |
| Julia | Youthful
| Female | Latin |
| Julie | Youthful: Jove's child. A feminine of Julian.
| Female | |
| Juliette | youthful | Female | |
| Jump | | Unisex | |
| Kali | after the Indian goddess of death | Female | Sanskrit |
| Karen | pure | Female | Danish |
| Karina | Italian, dear little one | Female | Scandinavian |
| Kate | Pure | Female | English |
| Katerina | Blessed, Pure, Holy | Unisex | Czechoslovakian |
| 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 |
| Kathleen | Innocent
| Female | Anglicized |
| Katie | Variant of Katherine. Pure.
| Female | English |
| Kelli | From The Wood | Unisex | Welsh |
| Kelly | Lively: aggressive.
| Female | Irish |
| Kendall | ruler of the valley | Female | English |
| Kenya | Animal Horn | Female | Hebrew |