Butler helped the Bulls earn the No. 3 seed in the Eastern Conference.
Golden State Warriors forward Draymond Green finished second, followed by Utah Jazz center Rudy Gobert and Miami Heat center Hassan Whiteside.
Butler averaged 20.0 points, 5.8 assists and 3.3 rebounds in 38.7 minutes per game this season, up from 13.1 points, 2.6 assists and 4.9 rebounds in 2013-14.
The fourth-year player's emergence helped the Bulls finish 50-32 and lock up a No. 3 seed in the Eastern Conference. Chicago is currently playing the Cleveland Cavaliers in the Eastern Conference semifinals.
Entering Wednesday night, Butler was averaging 24.1 points per game this postseason.
Miami Heat guard Goran Dragic won the award last season as a member of the Phoenix Suns.
- Stanley Kay