| Name | Meaning | Gender | Origin |
|---|
| Jack | From John - God's gracious gift | Male | English |
| Jacky | God Is Gracious | Unisex | English |
| Jacob | The supplanter, held by the heel | Male | Hebrew |
| Jacques | supplanter | Male | |
| Jago | A character in a Victorian book who battled against the odds | Male | Spanish |
| Jake | From Jacob - To fill the place of another | Male | Hebrew |
| Jakov | Supplanter, Representative | Unisex | Slavic |
| Jamee | supplanter, one who replaces | Unisex | |
| James | From Jacob - To fill the place of another, supplanter. | Male | English |
| Jameson | son of James | Male | English |
| Jeffery | Peaceful. Variant of Geoffrey in use since medieval times.
| Male | |
| Jeffrey | pledge of peace | Male | Spelling |
| Jim | supplanter | Male | English |
| Jimmy | supplanter | Male | English |
| Jock | God has been gracious: has shown favor. Based on John or Jacques.
| Male | Scottish |
| Kai | Fire
| Male | Hawaiian |
| Kiefer | barrel-maker | Male | |
| Kimo | Supplanter, Representative | Male | Hawaiian |
| Kiwi | | Unisex | Hebrew |
| Kizzie | Cinnamon tree | Unisex | Hebrew |
| Koa | Hawaiian for strong | Unisex | |
| Kobe | tortoise | Male | Swahili |
| Kyle | A place-name referring to the narrows: a wood or a church.
| Male | Scottish |
| Laleh | Tulip | Unisex | Persian |
| Lars | after the Metallica drummer Lars Ulrich | Male | Scandinavian |