After missing out on Myles Turner earlier in the weekend, the Celtics finally have their big man.
Cleveland drafted Thompson with the fourth overall pick in the 2011 draft out of Texas. Thompson provided the Cavs with a critically important presence in the paint during their 2016 NBA Finals win.
Thompson has produced for Cleveland, averaging a double-double the past two seasons after never having done so previously in his career.
Thompson averaged a double-double for Cleveland last season (12.0 points, 10.1 rebounds per game) and should provide an immediate boost in Boston's frontcourt, which lost Enes Kanter and Vincent Poirier to trades this week.
In the wake of Tristan Thompson's signing with the Boston Celtics, Thompson's now-former teammate Larry Nance Jr. offered a goodbye while also taking a jab at Thompson's jumping ability. He'll factor into the "big man" spot in the Celtics rotation with Daniel Theis and Robert Williams.
The move leaves the Celtics with about $4 million to spend, as the team continues to search for a backup point guard and bench shooter.