The 2009–10 Boston Celtics season was the 64th season of the franchise in the National Basketball Association (NBA). The Celtics finished with a record of 50–32, a 12 win drop off from the previous season. They finished 1st in the Atlantic Division and 4th in the Eastern Conference. In the playoffs, the Celtics defeated the Miami Heat in five games in the First Round, then defeated the top-seeded Cleveland Cavaliers (in a rematch of the 2008 Conference semifinals) again in six games in the Semifinals, and finally, defeated the second-seeded Orlando Magic (the runner-up of last year's Finals as well as the team that defeated the Celtics in last season's Conference semifinals in seven games) in six games in the conference finals to advance to the NBA Finals for the twenty-first time in franchise history. The Celtics made it back to the NBA Finals after a one-year hiatus and played against the defending NBA champion and their rival, the Los Angeles Lakers for the 12th time. In a rematch of the 2008 NBA Finals, in which the Celtics defeated the Lakers in six games to capture their seventeenth championship, the Celtics were defeated this time by the Lakers in seven games. The Celtics would not reach the Finals again until 2022 where they faced Golden State Warriors in a rematch of the 1964 NBA Finals and lost in six games.

Key dates

Summary

NBA Draft 2009

Free agency

Draft picks

Roster

Pre-season

(Hidalgo, Texas) || 0–1 recap (Newark, New Jersey) || 3–1 recap (Hartford, Connecticut) || 4–1 recap (Columbus, Ohio) || 6–2 recap

Regular season

Standings

Record vs. opponents

Game log

20,562 18,624 18,624 18,624 11,251 19,133 18,624 16,119 18,624 18,624 18,165 18,624 18,624 19,763 18,624 18,624 18,104 15,129 18,581 18,203 18,624 20,173 21,257 14,193 18,624 18624 18,624 17,461 19,060 19,259 18,422 18,624 19,600 15,149 19,800 18,624 14,112 18,624 18,624 17,375 18,624 18,624 17,461 18,732 18,624 20,173 18,624 18,624 18,624 14,848 14,439 18,997 20,618 19,818 18,624 18,624 18,624 17,956 18,624 19,008 18,624 14,316 18,624 18,624 20,562 18,624 18,624 18,198 20,488 19,911 18,624 18,624 18,624 18,624 18,624 18,624 19,763 18,793 18,624 18,717 20,649 18,624

Playoffs

Game log

18,624 18,624 19,500 19,520 18,624 20,562 20,562 18,624 18,624 20,562 18,624 17,461 17,461 18,624 18,624 17,461 18,624 18,997 18,997 18,624 18,624 18,624 18,997 18,997

Player statistics

Season

|| 7.0 1Stats with the Celtics.

Playoffs

Awards, records and milestones

Awards

Week/Month

All-Star

Season

Records

Milestones

Injuries and surgeries

Transactions