| Name | Meaning | Gender | Origin |
|---|
| Jemima | dove | Female | Hebrew |
| Jennifer | white shadow, white wave | Female | Cornish |
| Jenny | Diminutive of Jane and Jennifer.
| Female | English |
| Jenny | Diminutive of Jane and Jennifer.
| Female | English |
| Jess | Gift | Male | English |
| Jesse | wealthy | Male | Hebrew |
| Jessica | God's grace | Female | Hebrew |
| Jet | A deep black colour. Aircraft engine that propels an aircraft forward by expelling exhaust gases toward the rear. | Male | Mineral |
| Jinx | Charm, Spell | Female | Latin |
| Jones | God Will Bring | Male | Welsh |
| Josephine | God will increase | Female | |
| Jubilee | ram's horn | Female | Hebrew |
| Juniper | Juniper Tree | Female | English |
| Juno | queen of the heavens | Female | Latin |
| Kane | tribute, warrior; the doubly-accomplished, golden; man, the eastern sky; beautiful | Male | Celtic |
| Karma | Fate or destiny (Hinduism and Buddhism) | Female | Hindi |
| Katana | Sword | Unisex | Japanese |
| 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 |
| Katniss | | Female | |
| Katniss | | Female | |
| Kelly | Lively: aggressive.
| Female | Irish |
| Kid | | Unisex | Hebrew |
| Kinsey | victorious prince | Female | English |
| Kismet | fate, destiny | Female | Word |
| Kitty | Variant of Katherine. Pure.
| Female | English |