People who have competed at Australian events. Australia only, for now.
| Renegade Grappling |
| Olympia Robb | White | — |
| Olyvia Fernando | Yellow | De Been 100% Jiu Jitsu |
| Omandi Rangama | Grey | De Been 100% Jiu Jitsu |
| Omar Abood | Grey | DOMINANCE |
| Omar Annous | Blue | Integrated Combat Centre - Peakhurst |
| Omar Elhami | Purple | Sydney Wrestling Academy |
| Omar Mallah | Grey | Sydney Wrestling Academy |
| Omar Moussa | White | Bankstown Martial Arts |
| Omar Taleb | Grey | Australian Elite Team |
| Omari Papalii | White | FAIRFIELD MMA |
| Omer Hussain | White | Legion 13 HQ |
| Omi Doan | White | SOUTHSIDE BRAZILIAN JIU-JITSU OFFICIAL |
| Omkara Wrightson | Blue | The Ironfist Gym |
| Onyx Pawlowsky | White | Evolve Brazilian Jiu Jitsu |
| Onyx Ropati | Grey | SOUTHSIDE BRAZILIAN JIU-JITSU OFFICIAL |
| Opie Johnson | Grey | Team Lead |
| Orion Carr | Grey | Gracie Barra Liverpool |
| Orlando Barisic | Grey | Virtue Brazilian Jiu-Jitsu Australia |
| Orlando Broughton | Grey | Ortiz Martial Arts Academy |
Wave