The 2007–08 Boston Celtics season was the 62nd season of the Boston Celtics in the National Basketball Association (NBA). Powered by the offseason blockbuster acquisitions of perennial All-Stars Kevin Garnett and Ray Allen to join with established star Paul Pierce, the trade enabled the Celtics to finish the season with a record of 66-16 in addition to posting the best single-season turnaround in NBA history. The team also finished first in both the Atlantic Division and the Eastern Conference, and achieved the league's best record. The 66 wins were also the third-most in franchise history, behind the 1972–73 Celtics’ 68 wins and the famous 1985–86 Celtics’ 67 wins including 40 at home. Kevin Garnett was named NBA Defensive Player of the Year, while Danny Ainge, who executed "the most dramatic NBA turnaround ever", was named NBA Executive of the Year. The Celtics also sold out all 41 regular-season home games. The Celtics had the tenth best team offensive rating and the best team defensive rating in the NBA.

Walter Ray Allen Jr. is an American former professional basketball player. He played 18 seasons in the National Basketball Association (NBA) and was inducted into the Naismith Memorial Basketball Hall of Fame as a player in 2018. Allen is widely considered to be one of the greatest three-point shooters of all-time, and he held the record for most three-pointers made in a career from 2011 until 2021, when he was surpassed by Stephen Curry.