The 2011–12 Boston Celtics season was the 66th season of the franchise in the National Basketball Association (NBA). The Boston Celtics finished the regular season with a 39-27 won-loss record, which was the 4th best in the East, winning their 21st Atlantic Division title. Their longest winning and losing streaks were 5 games. The leading scorer was Paul Pierce, averaging 19.4 PPG. The leading rebounder was Kevin Garnett (8.2 RPG). Rajon Rondo led the team and the league in assists per-game with 11.7. The regular season was reduced from its usual 82 games to 66 due to the lockout. The Celtics made a relatively deep playoff run, challenging the Miami Heat in the Eastern Conference Finals. They ultimately lost in seven games. Following the season, Ray Allen left for the Heat, effectively ending the Big 3 era in Boston.

Via draft

Via free agency

Via trade

Via free agency

Negated Contract due to Injury

Waived

Retired

Many players signed with teams from other leagues due to the 2011 NBA lockout. FIBA allows players under NBA contracts to sign and play for teams from other leagues if the contracts have opt-out clauses that allow the players to return to the NBA if the lockout ends. The Chinese Basketball Association, however, only allows its clubs to sign foreign free agents who could play for at least the entire season.

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