Stars general manager Jim Nill released a statement regarding the decision and cited "unprofessional conduct" as the reason for Montgomery's dismissal:
"The Dallas Stars expect all of our employees to act with integrity and exhibit professional behavior while working for and representing our organization. This decision was made due to unprofessional conduct inconsistent with the core values and beliefs of the Dallas Stars and the National Hockey League."
Montgomery was in the midst of his second season as the Stars' head coach, and they currently own the No. 1 wild-card spot in the Western Conference with 37 points (17-11-3).
Last season, Dallas went 43-32-7 under Montgomery and reached the second round of the playoffs where it fell to the eventual Stanley Cup champion St. Louis Blues in seven games. All told, the Stars went 60-43-10 in just under one-an-a-half years with Montgomery as their head coach.
Montgomery, 50, spent parts of five seasons in the NHL as a center with the Blues, Montreal Canadiens, Philadelphia Flyers, San Jose Sharks and Stars. After his playing career ended, he gained extensive experience as a coach in the college ranks and the USHL.
Following stints as an assistant at Notre Dame and RPI, Montgomery was the head coach of Dubuque in the USHL from 2010-2013 and then the University of Denver from 2013-2018. Montgomery twice led Denver to the Frozen Four, including a national championship in 2017.
Bowness has 463 games of NHL head coaching experience with the Winnipeg Jets, Boston Bruins, Ottawa Senators, New York Islanders and Arizona Coyotes. He owns a record of just 123-289-48-3 with one playoff appearance.
He was hired as an assistant under Montgomery prior to the start of last season following a lengthy stint on the Tampa Bay Lightning's coaching staff.
Bowness will serve as the head coach Tuesday when Dallas hosts the New Jersey Devils.