Sorted alphabetically by last name · 2711 fighters
| Name | Nickname | |
|---|---|---|
| RP | Robert Peralta | "Problems" |
| RR | Robert Ruchala | |
| RS | Robert Sanchez | "Littlefury" |
| RV | Robert Valentin | "Robzilla" |
| RW | Robert Whiteford | "The Hammer" |
| RW | Robert Whittaker | "The Reaper" |
| RR | Roberto Romero | "El Charro Negro" |
| RT | Roberto Traven | "Spider" |
| RL | Rocky Lee | |
| RW | Rodney Wallace | "Shonuff the Master" |