The 1984–85 QMJHL season was the 16th season in the history of the Quebec Major Junior Hockey League. The league experimented for season, awarding one point for an overtime loss. Points for an overtime loss would not be awarded again until the 1999–2000 QMJHL season. The Plattsburgh Pioneers were admitted to the league as an expansion team, and the first QMJHL franchise based in the United States. It was the second league expansion in three seasons, having added two franchise in the 1982–83 QMJHL season, bringing the league up to twelve teams. The league did not have an expansion draft. The Pioneers featured an all-American lineup of players, who were not playing in the NCAA. The team folded after losing its first 17 games in 1984. Games played against the Pioneers and the points earned, were not included in the final standings. The remaining eleven teams played 68 games each which counted in the regular season standings. The Shawinigan Cataractes finished first overall in the regular season, winning the Jean Rougeau Trophy. The Verdun Junior Canadiens won the President's Cup, defeating the Chicoutimi Saguenéens in the finals. Coach Jean Bégin had been fired by the Laval Voisins after 19 games, then is hired by the Verdun Junior Canadiens with five games remaining in the season, leading the team to a league championship.

Team changes

Final standings

Note: GP = Games played; W = Wins; L = Losses; T = Ties; OL = Overtime loss; PTS = Points; GF = Goals for; GA = Goals against ‡Games played against the Plattsburgh Pioneers and the points earned, were not included in the final standings.

Scoring leaders

Note: GP = Games played; G = Goals; A = Assists; Pts = Points; PIM = Penalties in Minutes

Playoffs

Claude Lemieux was the leading scorer of the playoffs with 40 points (23 goals, 17 assists).

All-star teams

Trophies and awards