2010-11: Alexandre Belanger played for the Magog Cantonniers minor midget AAA team and skated for Team Quebec in the 2011 Canada Winter Games. In 26 games he was 14-9-1 with 1 shutout and had a 3.36 goals against and .885 save percentage. Magog was third in the Reebok Division and reached the playoff semifinals. Belanger was 6-3 in the playoffs with 1 shutout and had a 2.62 goals against and .906 save percentage. In four games for silver medal-winning Team Quebec at the CWG he had a 4.64 goals against and .887 save percentage. Belanger was selected by Rouyn-Noranda in the first round (18th overall) of the 2011 QMJHL Entry Draft.
2011-12: Belanger made his QMJHL debut as a 16-year-old, appearing in one game in September and another in December for the Rouyn-Noranda Huskies. He played in 33 games for Magog in his second season with the Cantonniers and was in net for Canada Quebec at the 2012 U17 World Hockey Challenge. He was 0-1 with a 2.12 goals against and .897 save percentage, stopping 35 of 39 shots with the Huskies. Belanger finished 14-15 in 33 games for Magog with a 3.00 goals against and .889 save percentage. Magog was fourth in the Reebok Division and reached the playoff quarterfinals. Belanger was 4-4 in the playoffs with a 3.12 goals against and .882 save percentage. In three games for Canada Quebec at the WHC he had a 5.07 goals against and .868 save percentage.
2012-13: Belanger took over the starting role for Rouyn-Noranda as a QMJHL rookie and handled the bulk of the goaltending for the Huskies during their run to the playoff semifinals. Sharing the goaltending with veteran Robin Gusse in the first half of the season, Belanger played in 44 games and was 24-13-1 with 1 shutout and posted a 3.46 goals against and .875 save percentage. In fourteen playoff games he was 8-5 with a 3.55 goals against and .874 save percentage. Ranked 14th amongst North American goaltenders in Central Scouting's final rankings, Belanger was selected by Minnesota in the seventh round (200th overall) of the 2013 NHL Draft.
Will be the starter for Rouyn-Noranda again in 2013-14. Belanger is not a big goaltender by contemporary standards but displays good technique and athleticism.