1980 Stanley Cup playoffs

The 1980 Stanley Cup playoffs, the playoff tournament of the National Hockey League (NHL) began on April 8, after the conclusion of the 1979–80 NHL season. This season saw the addition of four teams from the disbanded World Hockey Association (WHA) as expansion franchises, and thus the playoffs were also expanded from 12 to 16 teams. The expanded playoff format allowed two of those former WHA clubs, the Edmonton Oilers and the Hartford Whalers, to make the playoffs in their first season in the NHL. The Atlanta Flames played their final playoff games before moving to Calgary after the season; the playoffs would eventually return to Atlanta in 2007 when the expansion Atlanta Thrashers made their first postseason appearance.

The playoffs concluded on May 24 when the New York Islanders defeated the Philadelphia Flyers 5–4 to win the final series four games to two and win the Stanley Cup. It was the Islanders' first Stanley Cup win and was the first of four consecutive Stanley Cup wins.

Changes
With the league expansion from 17 to 21 teams, the playoffs were also expanded, from a 12-team tournament to a 16-team tournament. The sixteen teams were composed of the four divisional champions plus the top 12 finishers of the remaining 17 teams. The 16 qualifying teams were then seeded based on regular season points, with divisional rankings ignored. Division leaders no longer received first round byes. The teams were seeded 1 through 16, with the top team playing the 16th team in the first round, and so on. In subsequent rounds, matchups were similarly arranged, with the top remaining seed against the lowest remaining seed, and so on. The Preliminary Round was expanded to be a best-of-five set, up from a best-of-three.

Playoff seeds
The sixteen teams that qualified for the playoffs are ranked 1–16 based on regular season points.
 * 1) Philadelphia Flyers, Patrick Division champions, Clarence Campbell Conference regular season champions, NHL regular season champions – 116 points
 * 2) Buffalo Sabres, Adams Division champions, Prince of Wales Conference regular season champions – 110 points
 * 3) Montreal Canadiens, Norris Division champions – 107 points
 * 4) Boston Bruins – 105 points
 * 5) New York Islanders – 91 points
 * 6) Minnesota North Stars – 88 points
 * 7) Chicago Black Hawks, Smythe Division champions – 87 points
 * 8) New York Rangers – 86 points
 * 9) Atlanta Flames – 83 points
 * 10) St. Louis Blues – 80 points
 * 11) Toronto Maple Leafs – 75 points
 * 12) Los Angeles Kings – 74 points
 * 13) Pittsburgh Penguins – 73 points (30 wins)
 * 14) Hartford Whalers – 73 points (27 wins)
 * 15) Vancouver Canucks – 70 points
 * 16) Edmonton Oilers – 69 points

(1) Philadelphia Flyers vs. (16) Edmonton Oilers
This was the first playoff series meeting between these two teams.

(2) Buffalo Sabres vs. (15) Vancouver Canucks
This was the first playoff series meeting between these two teams.

(3) Montreal Canadiens vs. (14) Hartford Whalers
This was the first playoff series meeting between these two teams.

(4) Boston Bruins vs. (13) Pittsburgh Penguins
This was the second playoff series meeting between these two teams. This was a rematch of the previous year's Stanley Cup Quarterfinals, which Boston won in a four-game sweep.

(5) New York Islanders vs. (12) Los Angeles Kings
This was the first playoff series meeting between these two teams.

(6) Minnesota North Stars vs. (11) Toronto Maple Leafs
This was the first playoff series meeting between these two teams.

(7) Chicago Black Hawks vs. (10) St. Louis Blues
This was the second playoff series meeting between these two teams. Chicago won the only previous meeting in five games in the 1973 Stanley Cup Quarterfinals.

With their victory in Game one, Chicago snapped a record 16-game losing streak in the Stanley Cup playoffs.

(8) New York Rangers vs. (9) Atlanta Flames
This was the first playoff series meeting between these two teams. Game four was also the final home game for the Flames in Atlanta, as the franchise was sold and relocated to Calgary during the offseason.

(1) Philadelphia Flyers vs. (8) New York Rangers
This was the third playoff series meeting between these two teams. Both teams split their previous two meetings. This was a rematch of the previous year's Stanley Cup Quarterfinals, which New York won in five games.

(2) Buffalo Sabres vs. (7) Chicago Black Hawks
This was the second playoff series meeting between these two teams. Buffalo won the only previous meeting in five games in the 1975 Stanley Cup Quarterfinals.

(3) Montreal Canadiens vs. (6) Minnesota North Stars
This was the second playoff series meeting between these two teams. Montreal won the only previous meeting in six games in the 1971 Stanley Cup Semifinals. This was Montreal's first playoff series loss since losing to Buffalo in the 1975 Stanley Cup Semifinals.

(4) Boston Bruins vs. (5) New York Islanders
This was the first playoff series meeting between these two teams.

(1) Philadelphia Flyers vs. (4) Minnesota North Stars
This was the second playoff series meeting between these two teams. Philadelphia won the only previous meeting in six games in the 1973 Stanley Cup Quarterfinals.

(2) Buffalo Sabres vs. (3) New York Islanders
This was the third playoff series meeting between these two teams. New York won both previous meetings in consecutive years, the latter of which was a four-game sweep in the 1977 Stanley Cup Quarterfinals.

Stanley Cup Finals
This was the second playoff series (and only Finals) meeting between these two teams. Philadelphia won the only previous meeting in seven games in the 1975 Stanley Cup Semifinals.

Ken Morrow became the first player in history to win an Olympic Gold Medal and the Stanley Cup in the same season. Game six was the last NHL game to air on American network television for nearly ten years.