Atkinson received 59 first-place votes and 401 in total after leading the Cavaliers to a 64-18 season in his first year as head coach, the second-best record in franchise history and just three wins short of breaking the record set by the 2008-2009 team (66 wins).
Detroit Pistons head coach J.B. Bickerstaff came in second while Houston Rockets head coach Ime Udoka placed third.
Atkinson spent seven years in the NBA as an assistant coach for multiple teams, most recently the Golden State Warriors, and was the head coach of the Brooklyn Nets from 2016-2020, before being hired by Cleveland.
Cleveland finished as the No. 1 seed in the Eastern Conference and the second-best record in the NBA this season.
After advancing to the second round of the playoffs, the Cavs dropped Game 1 of the series to the Indiana Pacers on Sunday.
Game 2 will take place on Tuesday, May 6th, in Cleveland.