The 1991 Calder Cup Playoffs of the American Hockey League began on April 2, 1991. Ten teams, five from each division, qualified for the playoffs. The top 3 teams in each division received a bye for the preliminary round while the fourth- and fifth-placed teams in each division played a two-game, total goal series with the winners advancing to the Division Semifinals. The eight remaining teams then 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, 1991 with the Springfield Indians defeating the Rochester Americans four games to two to win the Calder Cup for the second consecutive year, and the seventh and final time in team history. This was a rematch of the 1990 Calder Cup Final where Springfield defeated Rochester four games to two. Similarly, a Springfield goaltender—this time Kay Whitmore -- won the Jack A. Butterfield Trophy as the MVP of the playoffs.
After the 1990-91 AHL regular season, the top five teams from each division qualified for the playoffs. The Rochester Americans finished the regular season with the best overall record.
In the preliminary round, the fourth-placed team is the home team for both games of the total-goal series. In each subsequent 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.
Preliminary Round[]
Note: Home team is listed first.
Northern Division[]
(4) Fredericton Canadiens vs. (5) Maine Mariners[]
April 2
Fredericton Canadiens
7 - 2
Maine Mariners
April 3
Fredericton Canadiens
4 - 5
Maine Mariners
Fredericton won 11 - 7 on aggregate.
Southern Division[]
(4) Hershey Bears vs. (5) Adirondack Red Wings[]
April 2
Hershey Bears
2 - 3
OT
Adirondack Red Wings
April 3
Hershey Bears
11 - 1
Adirondack Red Wings
Hershey won 13 - 4 on aggregate.
Division Semifinals[]
Northern Division[]
(1) Springfield Falcons vs. (4) Fredericton Canadiens[]
April 6
Springfield Falcons
3 - 4
OT
Fredericton Canadiens
April 8
Springfield Falcons
8 - 2
Fredericton Canadiens
April 12
Fredericton Canadiens
5 - 4
OT
Springfield Falcons
April 14
Fredericton Canadiens
4 - 1
Springfield Falcons
April 16
Springfield Falcons
2 - 1
OT
Fredericton Canadiens
April 18
Fredericton Canadiens
2 - 4
Springfield Falcons
April 20
Springfield Falcons
6 - 3
Fredericton Canadiens
Springfield won series 4 – 3
(2) Cape Breton Oilers vs. (3) Moncton Hawks[]
April 5
Cape Breton Oilers
4 - 5
OT
Moncton Hawks
April 6
Cape Breton Oilers
4 - 6
Moncton Hawks
April 8
Moncton Hawks
5 - 4
OT
Cape Breton Oilers
April 10
Moncton Hawks
3 - 1
Cape Breton Oilers
Moncton won series 4 - 0
Southern Division[]
(1) Rochester Americans vs. (4) Hershey Bears[]
April 5
Rochester Americans
3 - 4
OT
Hershey Bears
April 7
Rochester Americans
4 - 1
Hershey Bears
April 9
Hershey Bears
4 - 7
Rochester Americans
April 11
Hershey Bears
2 - 5
Rochester Americans
April 13
Rochester Americans
4 - 1
Hershey Bears
Rochester won series 4 - 1
(2) Binghamton Rangers vs. (3) Baltimore Skipjacks[]
April 5
Binghamton Rangers
5 - 4
Baltimore Skipjacks
April 6
Binghamton Rangers
2 - 0
Baltimore Skipjacks
April 11
Baltimore Skipjacks
3 - 6
Binghamton Rangers
April 13
Baltimore Skipjacks
6 - 5
Binghamton Rangers
April 17
Binghamton Rangers
3 - 5
Baltimore Skipjacks
April 19
Baltimore Skipjacks
1 - 2
Binghamton Rangers
Binghamton won series 4 - 2
Division Finals[]
Northern Division[]
(1) Springfield Indians vs. (3) Moncton Hawks[]
April 24
Springfield Indians
3 - 4
Moncton Hawks
April 26
Springfield Indians
3 - 2
Moncton Hawks
April 30
Moncton Hawks
2 - 9
Springfield Indians
May 2
Moncton Hawks
3 - 5
Springfield Indians
May 4
Springfield Indians
2 - 1
Moncton Hawks
Springfield won series 4 - 1
Southern Division[]
(1) Rochester Americans vs. (2) Binghamton Rangers[]
April 24
Rochester Americans
8 - 5
Binghamton Rangers
April 26
Binghamton Rangers
1 - 4
Rochester Americans
April 28
Rochester Americans
4 - 3
OT
Binghamton Rangers
April 29
Binghamton Rangers
4 - 6
Rochester Americans
Rochester won series 4 - 0
Calder Cup Final[]
(S1) Rochester Americans vs. (N1) Springfield Indians[]