The 1941–42 NHL season was the 25th season of the National Hockey League. Seven teams played 48 games each. The Toronto Maple Leafs would win the Stanley Cup defeating the Detroit Red Wings winning four straight after losing the first three in a best-of-seven series. No other team has repeated such a feat since.
The Americans started the season without Harvey "Busher" Jackson who refused to sign. He was then sold to Boston. But the Amerks had two positive notes: two defencemen, Tommy Anderson and Pat Egan, were now All-Star calibre. That didn't prevent them from finishing last, though. On December 9, 1941, the Chicago Blackhawks-Boston Bruins game would be delayed for over a half hour as United States President Franklin Delano Roosevelt declared that America was at war. 
Frank Patrick suffered a heart attack and had to sell his interest in the Montreal Canadiens, and the Habs almost had to move to Cleveland. But Tommy Gorman kept the team alive. They added Emile "Butch" Bouchard to start his great career on defence and another very good player, Buddy O'Connor, at centre. Montreal had goaltending problems as Bert Gardiner slumped, and rookie Paul Bibeault replaced him. He showed flashes of brilliance, but his inexperience showed. Joe Benoit starred with 20 goals, the first Canadien to do that since 1938–39, when Toe Blake did it.
The New York Rangers had a new goaltender as Sugar Jim Henry replaced the retired Dave Kerr. Henry was one of the reasons the Rangers finished first, something they would not again do for the next 50 years.