The 1970–71 NBA season was the 25th season of the National Basketball Association. The season ended with the Milwaukee Bucks winning the NBA Championship, beating the Baltimore Bullets 4 games to 0 in the NBA Finals. Three new teams made their debut: the Cleveland Cavaliers, the Portland Trail Blazers, and the Buffalo Braves.
* The NBA expanded to 17 teams as the Portland Trail Blazers, Buffalo Braves, and Cleveland Cavaliers began play. For the first time, the league was divided into Conferences (East and West), each with two divisions. The Detroit Pistons and Milwaukee Bucks were shifted from the old Eastern Division to the Western Conference's Midwest Division, and the Atlanta Hawks were switched from the Western Division to the Eastern Conference's Central Division.
* The 1971 NBA All-Star Game was played at the San Diego Sports Arena in San Diego, California, with the West beating the East 108-107. Lenny Wilkens of the Seattle SuperSonics won the game's MVP award.
* In only their third year of existence, the Bucks won the NBA Championship, sweeping the Baltimore Bullets in four straight games.