1977–78 Boston Celtics season

The 1977–78 Boston Celtics season was the 32nd season of the Boston Celtics in the National Basketball Association (NBA) and was linked to the Buffalo Braves season. While the Braves were struggling on the court, their owner John Y. Brown brokered a deal to take over the legendary Celtics franchise. Celtics owner Irv Levin wanted to move the franchise to California, however, the NBA would not allow him to take the cornerstone franchise out of Boston.

NBA lawyer (and future commissioner) David Stern offered a comprise in which Levin and Brown would swap franchises, so that Levin could take over the Braves and move them to San Diego. The Braves, ironically, played their last game of the season in Boston. Eventually, the owners of the 22 franchises voted 21–1 to approve the deal, and the Braves moved from Buffalo to San Diego. The deal also included a 7-player trade in which the Celtics acquired Nate Archibald, Billy Knight and Marvin Barnes in exchange for Freeman Williams, Kevin Kunnert, Kermit Washington and Sidney Wicks. The Braves would not request a draft pick in the deal, allowing the Celtics to retain the draft rights to future Hall of Famer Larry Bird.

This was one of only three seasons from 1951 to 1993 that the Celtics finished with a losing record. This was the 16th and final season for the legendary John Havlicek. No person has played more seasons for the Celtics than Havlicek.