Poids Mouches Hommes
 | Juan Puerta | 1-0-0 REC | #7100 |  |
 | Juancamilo Ronderos | 0-2-0 UFC | #4892 |  |
 | Jung Hyun Lee | 1-2-0 REC | #1531 |  |
 | Junior Assis | 0-1-0 REC | #7380 |  |
 | Juscelino Pantoja | 0-1-0 REC | #6147 | |
 | Jussier da Silva | 9-7-0 UFC | #1043 | |
 | Justin Scoggins | 4-5-0 UFC | #2674 | |
 | Kai Kara-France | 8-5-0 UFC | #534 |  |
 | Kai Yoshida | 0-1-0 REC | #5238 |  |
 | Kaito Oda | 0-1-0 REC | #5997 | |
 | Kanean Catron | 1-0-0 REC | #1452 | |
 | Kayck Alencar | 0-1-0 REC | #6286 | |
 | Kendrick Latchman | 0-1-0 REC | #6061 | |
 | Kentaro Tomita | 0-1-0 REC | #6825 | |
 | Kevin Borjas | 2-4-0 UFC | #577 |  |
 | Kevin Fernandez | 4-0-0 REC | #1214 | |
 | Keynan Davis | 1-2-0 REC | #5272 | |
 | Khamzat Ilyasov | 1-1-0 REC | #3012 |  |
 | Khavid Dakaev | 2-0-0 REC | #1861 | |
 | King Rikuto | #7846 | |