The school says Montgomery will be officially introduced at a news conference on campus on Saturday.
Montgomery spent 18 years with the Cardinal. He's been out of coaching since August 2006 when he was let go after two seasons in the NBA with the Golden State Warriors. He has announced college games and been an assistant athletic director at Stanford while still collecting money from the final two years of his contract with Golden State.
Braun was fired last week after 12 seasons as coach when the Bears missed the NCAA tournament for the fourth time in five years.