McNichols Sports Arena was an indoor arena located in Denver, Colorado. Located adjacent to Mile High Stadium and completed in 1975, at a cost of $16 million, it seated 16,061 for hockey games, 17,171 for basketball games and contained 27 luxury suites, which were installed as part of a 1986 renovation. It was named after Denver mayor William H. McNichols, Jr., who served from 1968 to 1983. A small-scale scandal surrounded the naming, because “Bill” McNichols was in office at the time. The 1986 renovations also saw the original Stewart-Warner end-zone scoreboards, which each had color matrix screens, upgraded by White Way Sign with new digits and to include new color video screens.

The arena closed after the Nuggets and Avalanche moved to Pepsi Center and was demolished in 2000 to make space for a parking lot surrounding Broncos Stadium at Mile High.

McNichols Sports Arena was the home of the Denver Nuggets of the ABA and NBA for its entire existence from 1975 to 1999 It also hosted multiple hockey teams, including the Denver Spurs of the WHA during the 1975–76 season, the Colorado Rockies of the NHL from 1976 to 1982, the Colorado Flames of the CHL from 1982 to 1984, the Denver Grizzlies of the International Hockey League from 1994 to 1995, and the Colorado Avalanche of the NHL from 1995 to 1999.

McNichols hosted the NCAA Final Four in 1990, won by UNLV over Duke University and the West Regional Semifinal in 1996. It was also host to the 1976 ABA All-Star Game, in which the host Nuggets defeated the ABA All-Stars, games 1, 2, and 5 of the 1976 ABA finals, and the 1984 NBA All-Star Game. It also hosted games one and two of the Stanley Cup Finals in 1996, where the Colorado Avalanche defeated the Florida Panthers in four games to bring Denver its first major sports championship.

UFC 1, the first event of the Ultimate Fighting Championship, was held there in 1993.