| Name | Meaning | Gender | Origin |
|---|
| Ivory | The hard, smooth, yellowish-white of an elephant's tusk. | Male | Word |
| Izzie | | Unisex | Hebrew |
| Izzy | Salvation By God | Male | English |
| Jack | after the Georgetown University mascot, Jack the Bulldog | Male | English |
| Jack | From John - God's gracious gift | Male | English |
| Jack Frost | | Unisex | Hebrew |
| Jaeger | Hunter | Unisex | German |
| Jagger | a teamster | Male | English |
| James | From Jacob - To fill the place of another, supplanter. | Male | English |
| Jasper | Black stone
| Male | Persian |
| Jasper | Black stone
| Male | Persian |
| Jasper | Black stone
| Male | Persian |
| Jax | God has been gracious: has shown favor. Based on John or Jacques.
| Male | Modern |
| Jazz | The romantic music
| Male | Word |
| Jerry | after Jerry Garcia, The Grateful Dead | Male | English |
| Jersey | From A Section Of England | Male | English |
| Jeter | after Derek Sanderson Jeter, Yankee's shortstop | Male | |
| Jethro | excellence | Male | Hebrew |
| Jett | Jet Black Gem | Male | English |
| Jewels | Jewel | Unisex | English |
| Jo Jo | | Unisex | Hebrew |
| Johnnie | Modern feminine of John and Jon.
| Male | English |
| Jonathan | God gives | Male | Hebrew |
| Jones | God Will Bring | Male | Welsh |
| Josh | God Saves | Unisex | English |