The Celtics-Hawks rivalry is a rivalry in the Eastern Conference of the National Basketball Association that has lasted for over five decades, when the then-Tri-Cities Blackhawks joined the NBA as part of the National Basketball League and the Basketball Association of America merger. The two teams have faced each other eleven times in the NBA Playoffs, four times in the NBA Finals, with the Celtics winning ten of twelve series against the Hawks, including three out of four NBA Finals. The Hawks often managed to make their series with the Celtics memorable. The rivalry intensified in 2016 with Hawks All-Star Center Al Horford spurning the team and joining the Celtics.

The rivalry between the Celtics and the New York Knicks stems from the location of the teams, both of which are in the NBA's Atlantic division. The rivalry mirrors the fierce competition between the Boston and New York City sports teams, as evidenced by the Bruins-Rangers rivalry, Red Sox–Yankees rivalry and Jets–Patriots rivalry. Boston and New York are also the only two original NBA franchises that have remained in the same city for the duration of their existence. The teams have played 512 games against each other during the regular season, with the Celtics winning 276 times. The two teams have also faced each other 61 times during the playoffs, with the Celtics winning 34 times.

The rivalry between the Celtics and the Detroit Pistons peaked in the 1980s, featuring players such as Larry Bird, Kevin McHale, Robert Parish, Isiah Thomas, Bill Laimbeer, Dennis Rodman, and Joe Dumars. These teams met in the NBA Playoffs five times in 7 seasons from 1985 to 1991, with the Celtics winning in 1985 and 1987, and the Pistons coming out on top en route to back-to-back Finals appearances in 1988 and their championship seasons of 1989 and 1990. Led by Paul Pierce, Kevin Garnett and Ray Allen in the 2008 Eastern Conference Finals the Celtics defeated the Pistons in 6 games to advance to the NBA Finals where they went on to beat the Lakers also in 6 games.

The rivalry between the Boston Celtics and Los Angeles Lakers involves the two most storied franchises in NBA history. It has been called the NBA's best rivalry. The two teams have met a record twelve times in the NBA Finals, starting with their first Finals meeting in 1959. They would go on to dominate the league in the 1960s and the 1980s, facing each other six times in the 1960s, three times in the 1980s, in 2008, and in 2010. The rivalry had been less intense since the retirements of Magic Johnson and Larry Bird in the early 1990s, but in 2008 it was renewed as the Celtics and Lakers met in the Finals for the first time since 1987, with the Celtics winning the series in six games.

The most recent and unexpected rivalry that has been created between the Celtics is with the Washington Wizards. It started late in the 2015-16 season in a January regular season game after Jae Crowder was given a technical foul. Crowder then began to exchange words with then Wizards coach Randy Wittman. It began to escalate that off-season when the Celtics were trying to sign Al Horford. It was publicly reported that Jae Crowder emphasized that the Celtics beat the Wizards in all of their meetings that season and should sign with them rather than Washington. In their first meeting of the 2016-17 season, Wall hit Marcus Smart in the back-court when they were up by 20 late in the 4th quarter.