|Dates April 5–May 24, 1990|
Champions Edmonton Oilers
Runner-up Boston Bruins
|Semifinalists Chicago Blackhawks Washington Capitals|
The 1990 Stanley Cup playoffs for the National Hockey League (NHL) championship began on April 5, 1990, following the 1989–90 regular season. The sixteen teams that qualified, from the top four teams of the four divisions, played best-of-seven series with re-seeding after the division finals. The Conference Champions played a best-of-seven series for the Stanley Cup.
- Playoff seeds
- Adams Division
- Patrick Division
- Norris Division
- Smythe Division
- Stanley Cup Finals
This was the last time that the Detroit Red Wings missed the playoffs. They have since made the playoffs for 25 consecutive seasons.
Since entering the NHL as expansion teams in the 1967–68 NHL season this was the first and only time to date that both the Philadelphia Flyers and Pittsburgh Penguins missed the playoffs in the same season.
The playoffs concluded on May 24 with the Edmonton Oilers winning the Stanley Cup, defeating the Boston Bruins in the final series four games to one. Edmonton goaltender Bill Ranford was awarded the Conn Smythe Trophy as Most Valuable Player of the playoffs.
The following teams qualified for the playoffs:
- Boston Bruins, Adams Division champions, Prince of Wales Conference regular season champions, Presidents' Trophy winners – 101 points
- Buffalo Sabres – 98 points
- Montreal Canadiens – 93 points
- Hartford Whalers – 85 points
- New York Rangers, Patrick Division champions – 85 points
- New Jersey Devils – 83 points
- Washington Capitals – 78 points
- New York Islanders – 73 points
- Chicago Blackhawks, Norris Division champions – 88 points
- St. Louis Blues – 83 points
- Toronto Maple Leafs – 80 points
- Minnesota North Stars – 76 points
- Calgary Flames, Smythe Division champions, Clarence Campbell Conference regular season champions – 99 points
- Edmonton Oilers – 90 points
- Winnipeg Jets – 85 points
- Los Angeles Kings – 75 points
Stanley Cup Finals
The Edmonton Oilers defeated the Boston Bruins in five games. For the Oilers, it was their fifth Cup win in seven years, and their only one without Wayne Gretzky. In game one, Petr Klima scored at 15:13 of the third overtime period to give the Oilers a 3–2 win. The game broke the record for longest Final game, set in 1931 between Chicago and Montreal. This game remains the longest in Stanley Cup Final history (Longest NHL overtime games) to date, edging both Brett Hull's cup-winner in 1999 and Igor Larionov's game-winner in 2002 by less than 30 seconds. In game five at the Boston Garden on May 24 the Oilers won 4–1, Craig Simpson scored the game-winning goal.