| Name | Meaning | Gender | Origin |
|---|
| Houdini | | Male | Hebrew |
| Hulk | | Unisex | Hebrew |
| Hyde | hide | Male | English |
| Hydra | | Unisex | Hebrew |
| Ichabod | Glory has Departed | Male | Hebrew |
| Igor | Scottish variation of Welsh Ifor, lord or English form of Scandinavian Ifar, yew | Male | Russian |
| Imp | | Unisex | Hebrew |
| Ira | watchful, descendant | Male | Hebrew |
| IT | | Unisex | Hebrew |
| Jack | after the Georgetown University mascot, Jack the Bulldog | Male | English |
| Jack | From John - God's gracious gift | Male | English |
| Jack-o-Lantern | | Unisex | Hebrew |
| Jackson | Son of Jack | Male | English |
| Jason | the Lord is salvation | Male | Hebrew |
| Jasper | Black stone
| Male | Persian |
| Jasper | Black stone
| Male | Persian |
| Jasper | Black stone
| Male | Persian |
| Jaws | Bones that form the mouth. A dangerous situation - "The Jaws of Death" | Unisex | |
| Jax | God has been gracious: has shown favor. Based on John or Jacques.
| Male | Modern |
| Jekyll | | Unisex | Hebrew |
| Jet | A deep black colour. Aircraft engine that propels an aircraft forward by expelling exhaust gases toward the rear. | Male | Mineral |
| Jett | Jet Black Gem | Male | English |
| Job | The Persecuted | Male | Hebrew |
| John | God is merciful | Male | Hebrew |
| Jolly | Full of good humor and high spirits. | Unisex | |