Originally the 30th overall pick by Vegas in the 2021 NHL Draft, Dean skated in 49 games in 2023-24 for the Thunderbirds, posting 14 points (9g, 5a). Dean also made his NHL debut with the Blues on March 21, 2024 at Ottawa.
Dean was a member of Team Canada's gold-medal-winning World Junior Championship squad in 2022, where he posted three points and 33 penalty minutes in the seven-game tournament. In his final junior hockey season with the QMJHL's Gatineau Olympiques, Dean posted 70 points (33g, 37a) and a +39 rating in just 50 games before adding another 26 points (10g, 16a) in 13 QMJHL playoff contests.