UFC 21: Return of the Champions was a mixed martial arts event held by the Ultimate Fighting Championship on July 16, 1999 at the Five Seasons Events Center in Cedar Rapids, Iowa. The event was seen live on pay per view in the United States, and later released on home video.
UFC Fight Night 131: Rivera vs. Moraes
UFC 225: Whittaker vs. Romero 2
UFC Fight Night 132: Cowboy vs. Edwards
UFC 226: Miocic vs. Cormier
UFC Fight Night 133: dos Santos vs. Ivanov
UFC Fight Night 134: Shogun vs. Smith
UFC on Fox 30: Alvarez vs. Poirier 2
UFC 224: Nunes vs. Pennington
UFC Fight Night 129: Maia vs. Usman
UFC Fight Night 130: Thompson vs. Till
UFC 91: Couture vs. Lesnar
UFC 55: Fury
UFC 54: Boiling Point
UFC 53: Heavy Hitters
UFC 100: Lesnar vs. Mir 2
UFC 227: Dillashaw vs. Garbrandt 2
UFC 46: Supernatural
UFC Fight Night 18: Condit vs. Kampmann
UFC 99: The Comeback
UFC 101: Declaration