| Fighter | Record | Last Bout |
|---|---|---|
| Josias Musasa | 8-2-0 | 2025-09-27 |
| Jovan Leka | 14-2-0 | 2026-08-01 |
| Juan Diaz | 16-1-1 | 2026-05-16 |
| Julia Avila | 9-4-0 | 2025-02-15 |
| Julia Polastri | 15-6-0 | 2026-08-29 |
| Julian Erosa | 31-14-0 | 2026-03-28 |
| Julian Marquez | 9-6-0 | 2025-03-01 |
| Juliana Miller | 6-4-0 | 2026-08-08 |
| Julianna Pena | 13-6-0 | 2025-06-07 |
| Julien Leblanc | 10-3-0 | 2026-10-17 |
| Julija Stoliarenko | 11-10-2 | 2025-08-09 |
| Julius Walker | 7-3-0 | 2026-06-27 |
| Junior Tafa | 7-6-0 | 2026-06-06 |
| JunYong Park | 19-7-0 | 2025-10-25 |
| Justin Gaethje | 28-5-0 | 2026-06-14 |
| Justin Tafa | 7-5-0 (1 NC) | 2025-02-08 |
| Kaan Ofli | 15-4-1 | 2026-06-27 |
| Kai Asakura | 23-6-0 | 2026-08-29 |
| Kai Kamaka III | 18-8-1 | 2026-07-11 |
| Kai Kara-France | 25-12-0 (1 NC) | 2025-06-28 |
| Kamaru Usman | 21-5-0 | 2026-07-18 |
| Karine Silva | 19-7-0 | 2026-04-18 |
| Karol Rosa | 19-8-0 | 2026-06-20 |
| Karolina Kowalkiewicz | 16-10-0 | 2025-10-11 |
| Katlyn Cerminara | 18-6-0 | 2026-10-17 |
| Kaue Fernandes | 11-3-0 | 2026-08-15 |
| Kayla Harrison | 19-1-0 | 2025-06-07 |
| Keiichiro Nakamura | 8-1-0 | 2026-01-31 |
| Kelvin Gastelum | 21-11-0 (1 NC) | 2026-04-11 |
| Kennedy Nzechukwu | 14-7-1 | 2026-08-22 |
| Ketlen Souza | 17-6-0 | 2026-06-06 |
| Ketlen Vieira | 16-5-0 | 2026-05-16 |
| Kevin Borjas | 11-6-0 | 2026-08-29 |
| Kevin Christian | 9-4-0 | 2026-05-02 |
| Kevin Holland | 29-15-0 (1 NC) | 2026-04-11 |
| Kevin Jousset | 10-4-0 | 2025-02-08 |
| Kevin Vallejos | 18-1-0 | 2026-03-14 |
| Khalil Rountree Jr. | 15-7-0 (1 NC) | 2025-10-04 |
| Khamzat Chimaev | 15-1-0 | 2026-05-09 |
| Khaos Williams | 16-5-0 | 2026-10-03 |
| Kiefer Crosbie | 10-6-0 | 2025-08-23 |
| King Green | 36-17-1 (1 NC) | 2026-10-03 |
| Kiru Sahota | 12-3-0 | 2024-11-23 |
| Klaudia Sygula | 8-3-0 | 2026-09-05 |
| Kody Steele | 8-1-0 | 2026-05-02 |
| Kris Moutinho | 14-8-0 | 2026-02-28 |
| Kron Gracie | 5-3-0 | 2024-12-07 |
| Kurt Holobaugh | 22-10-0 (1 NC) | 2025-05-31 |
| Kurtis Campbell | 9-1-0 | 2026-09-05 |
| Kyle Daukaus | 17-5-0 (1 NC) | 2026-10-17 |