Poids Mouches Hommes
 | Joseph Benavidez | 15-6-0 UFC | #202 |  |
 | Joseph Camacho | 0-1-0 REC | #6525 |  |
 | Joseph Morales | 3-2-0 UFC | #690 | |
 | Josh Ferguson | 0-2-0 UFC | #4629 | |
 | Josh Sampo | 1-3-0 UFC | #3861 | |
 | Joshua Perreira | 1-0-0 REC | #6225 | |
 | Joshua Van | 9-1-0 UFC | #24 |  |
 | Josiah Reyes | 1-1-0 REC | #4965 | |
 | Jostin Quilca | 0-1-0 REC | #4929 |  |
 | Juan Puerta | 1-0-0 REC | #6369 | |
 | Juancamilo Ronderos | 0-2-0 UFC | #4756 |  |
 | Jung Hyun Lee | 1-2-0 REC | #486 |  |
 | Junior Assis | 0-1-0 REC | #6677 |  |
 | Juscelino Pantoja | 0-1-0 REC | #6033 | |
 | Jussier da Silva | 9-7-0 UFC | #944 | |
 | Justin Scoggins | 4-5-0 UFC | #2412 | |
 | Kai Asakura | 0-2-0 UFC | #727 |  |
 | Kai Kara-France | 8-5-0 UFC | #403 |  |
 | Kai Yoshida | 0-1-0 REC | #4539 | |
 | Kendrick Latchman | 0-1-0 REC | #6352 | |