2024–25 Boston Celtics season

The 2024–25 Boston Celtics season was the franchise's 79th season in the National Basketball Association (NBA). The Celtics entered the season as defending champions after winning the 2024 NBA Finals against the Dallas Mavericks in five games during the previous season for their NBA-record 18th championship and attempted to qualify for back-to-back Finals appearances for the first time since 1986 and 1987, as well as win back-to-back championships for the first time since 1968 and 1969. On their first game of the season, the Celtics would tie the NBA record for the most three-pointers made in a game. On March 15, the Celtics clinched their 11th consecutive playoff berth in a row since 2015 with a 115–113 win over the Brooklyn Nets.

In the first round, the Celtics dispatched the Orlando Magic in five games to advance to the conference semifinals. However, despite being considered major favorites for championship contention, the Celtics were upset in the second round by the New York Knicks in six games following a devastating Achilles injury to star player Jayson Tatum, marking the potential seventh straight year without a repeat champion, and the sixth in which the defending champions had failed to advance beyond the conference semifinals. This was the first time the Celtics were eliminated before the conference finals since 2021.