The 1985 Calder Cup Playoffs of the American Hockey League began on April 10, 1985. The eight teams that qualified, four from each division, played best-of-7 series for Division Semifinals and Division Finals. The division champions played a best-of-7 series for the Calder Cup. The Calder Cup Final ended on May 24, 1985 with the Sherbrooke Canadiens defeating the Baltimore Skipjacks four games to two to win the Calder Cup for the only time in team history. Sherbrooke's Brian Skrudland won the Jack A. Butterfield Trophy as AHL playoff MVP.
The Maine Mariners set an AHL playoff record during the Northern division final against Sherbrooke by scoring three goals 23 seconds apart. Maine scored at 19:29, 19:42, and 19:52 of the second period in the game, thereby setting a new AHL playoff record for the three fastest goals scored.
In each round, the team that earned more points during the regular season receives home ice advantage, meaning they receive the "extra" game on home-ice if the series reaches the maximum number of games. There is no set series format due to arena scheduling conflicts and travel considerations.