Sorted alphabetically by last name · 2715 fighters
| Name | Nickname | |
|---|---|---|
| JA | Junior Albini | "Baby" |
| JA | Junior Assuncao | |
| JD | Junior Dos Santos | "Cigano" |
| JT | Junior Tafa | "The Juggernaut" |
| JF | Jussier Formiga | |
| JB | Justin Buchholz | |
| JE | Justin Edwards | "Fast Eddy" |
| JE | Justin Eilers | "The Hammer" |
| JF | Justin Frazier | "The Grizzly Bear" |
| JG | Justin Gaethje | "The Highlight" |