After his playing career ended in 2009, Lue became Director of Basketball Development for the Boston Celtics. In 2014, he was hired by the Cavaliers as associate head coach. Lue was promoted to head coach during the 2015–16 season, replacing the fired David Blatt. That same season, Lue coached the Cavaliers to their first NBA championship and became one of the few rookie coaches in the NBA to ever lead his team to a title. Lue coached the Cavaliers to the NBA Finals in the 2016–17 and 2017–18 seasons; in both seasons, the Cavaliers were defeated by the Golden State Warriors in the NBA Finals. Lue was fired by Cleveland in October 2018.