ONE 166: Qatar was a combat sport event produced by ONE Championship that took place on March 1, 2024, at Lusail Sports Arena in Lusail, Qatar. A ONE Middleweight World Championship bout between current champion Reinier de Ridder (also former ONE Light Heavyweight World Champion) and the ONE Light Heavyweight and Heavyweight Champion Anatoly Malykhin headlined the event.
| Actor | Role |
|---|---|
 Anatoliy MalykhinSelf | Self |
 Reinier De RidderSelf | Self |
 Tang KaiSelf | Self |
 Thanh LeSelf | Self |
 Joshua PacioSelf | Self |
 Jarred BrooksSelf | Self |
 Amir AliakbariSelf | Self |
 Arjan BhullarSelf | Self |
 Mehdi ZatoutSelf | Self |
 Zuhayr Al-QahtaniSelf | Self |
| VVladimir KuzminSelf | Self |
| ZZafer SayikSelf | Self |
 Cleber SousaSelf | Self |
| OOsamah AlmarwaiSelf | Self |
| AAli SaldoevSelf | Self |
| ZZakaria El JamariSelf | Self |
| SShinji SuzukiSelf | Self |
| HHan ZihaoSelf | Self |
| KKeito YamakitaSelf | Self |
| JJeremy MiadoSelf | Self |