| Name | Meaning | Gender | Origin |
|---|
| Inky | | Unisex | Hebrew |
| Irene | Peace
| Female | Greek |
| Ishtar | goddess | Unisex | |
| Isis | throne | Female | Egyptian |
| Ivy | ivy plant, a wine | Female | Plant |
| Izzy | Salvation By God | Male | English |
| Jada | wise | Female | Spanish |
| Jasmine | Flower
| Female | Persian |
| Jason | the Lord is salvation | Male | Hebrew |
| Javan | Son of Japtheth
| Male | Hebrew |
| Jellylorum | | Unisex | Hebrew |
| Jennifer | white shadow, white wave | Female | Cornish |
| Jet | A deep black colour. Aircraft engine that propels an aircraft forward by expelling exhaust gases toward the rear. | Male | Mineral |
| Jibril | archangel Gabriel | Unisex | |
| Kachina | Sacred Dancer | Unisex | Native American |
| Kader | Able | Unisex | Arabic |
| Kafka | jackdaw | Male | Czech |
| Kala | time, black | Unisex | |
| Kali | after the Indian goddess of death | Female | Sanskrit |
| Kane | tribute, warrior; the doubly-accomplished, golden; man, the eastern sky; beautiful | Male | Celtic |
| 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 |
| Katy | pure | Female | Short |
| Katy | pure | Female | Short |
| Keenan | Ancient
| Male | Irish |
| Kelly | Lively: aggressive.
| Female | Irish |