| Name | Meaning | Gender | Origin |
|---|
| Jennie | English, God's gracious gift | Female | English |
| Jennifer | white shadow, white wave | Female | Cornish |
| Jenny | Diminutive of Jane and Jennifer.
| Female | English |
| Jenny | Diminutive of Jane and Jennifer.
| Female | English |
| Jester | A fool at medieval courts | Unisex | |
| Jezzamyn | | Unisex | Hebrew |
| Jim Crow | | Unisex | Hebrew |
| Johnny Rotten | | Unisex | Hebrew |
| Jonquil | Reed | Female | English |
| Junior Mint | | Unisex | Hebrew |
| Juno | queen of the heavens | Female | Latin |
| Kali | after the Indian goddess of death | Female | Sanskrit |
| Kamen | Rock | Unisex | Croatian |
| Kami | Loving | Unisex | Hindu |
| Kapuk | | Unisex | |
| Kat | 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 |
| Kathren | Pure, Chaste | Unisex | Not Available |
| Katianna | | Unisex | |
| Katie | Variant of Katherine. Pure.
| Female | English |
| Kazuo | Harmonious Man | Unisex | Japanese |
| Kenai | | Unisex | Hebrew |
| Kendra | Blend of Ken: (royal obligation:clear water) and Sandra: (protector of man) or Andrea: (manly or masculine).
| Female | English |
| Keno | | Unisex | Hebrew |