UFC 266: Volkanovski vs. Ortega was a mixed martial arts event produced by the Ultimate Fighting Championship that took place on September 25, 2021 at the T-Mobile Arena in Paradise, Nevada, part of the Las Vegas Metropolitan Area, United States. A UFC Featherweight Championship bout between current champion Alexander Volkanovski and former title challenger Brian Ortega headlined the event.

• Ultimate Fighting Championship
• Alexander Volkanovski
• Brian Ortega
• Valentina Shevchenko
• Lauren Murphy
• Robbie Lawler
• Nick Diaz
• Curtis Blaydes
• Jairzinho Rozenstruik