The Anaheim Ducks selected Montour, an offensive-minded defenseman, in the second round (No. 55) of the 2014 NHL Draft after he had 62 points (14 goals, 48 assists) in 60 games with Waterloo of the United States Hockey League. He played for the University of Massachusetts-Amherst in 2014-15 before signing with the Ducks and playing 14 games for Norfolk, their American Hockey League affiliate.
Montour spent all of the 2015-16 season with San Diego after the Ducks relocated their AHL team and was named a First-Team All-Star and a member of the All-Rookie team. He spent the first half of 2016-17 there before being called up to the NHL. Montour made his NHL debut on Dec. 29, 2016, and scored his first NHL goal in his sixth game, against the Tampa Bay Lightning on Feb. 6, 2017.