Sorted alphabetically by last name · 2778 fighters
| Name | Nickname | |
|---|---|---|
| RV | Robert Valentin | "Robzilla" |
| RW | Robert Whiteford | "The Hammer" |
| RW | Robert Whittaker | "The Reaper" |
| RR | Roberto Romero | "El Charro Negro" |
| RS | Roberto Soldic | "Robocop" |
| RT | Roberto Traven | "Spider" |
| RL | Rocky Lee | |
| RW |
| Rodney Wallace |
| "Shonuff the Master" |
| RB | Rodolfo Bellato | "Trator" |
| RR | Rodolfo Rubio Perez | "Fito" |