1945–46 NHL season

League business

CAHA secretary George Dudley insisted that tryout contracts be honoured and that junior-aged players on NHL reserve lists be reinstated as amateurs to rejoin the CAHA. The wartime practice of borrowing amateurs for three games or fewer was ended. The NHL proposed a flat $20,000 payment for signing amateurs, which Dudley considered too low, but the CAHA ultimately accepted the lump sum to maintain its alliance with the NHL. Synchronized red lights for goals became mandatory at all NHL rinks. Lester Patrick retired as general manager of the New York Rangers on February 22, 1946, remaining as vice president of Madison Square Garden. The NHL and the International Ice Hockey Association agreed to mutually enforce suspensions for players who failed to fulfill a tryout contract.

Regular season

The 1945–46 NHL season saw many World War II veterans return to their teams, though most struggled to find their old form. Boston Bruins goaltender Frank Brimsek, once nicknamed "Mr. Zero," was one exception; after a rough start where he allowed eight goals in a game against Chicago, he steadily improved and eventually made the Second All-Star Team. The Bruins briefly held first place but finished second. Chicago's Max Bentley led the league in scoring, and his "Pony Line" with brother Doug and Bill Mosienko pushed the Black Hawks into first place until Doug Bentley injured his knee on January 23, causing the team to fade.

Frank Patrick, a former Pacific Coast Hockey Association president and NHL managing director, suffered a heart attack and spent weeks in the hospital. On January 30, defenceman Babe Pratt was expelled from the NHL for betting on games, but he appealed, promising to stop, and was reinstated after missing nine games. Toronto's Gaye Stewart led the league with 37 goals, but the Maple Leafs finished fifth and missed the playoffs for the first time since moving to Maple Leaf Gardens.

Bill Durnan tied George Hainsworth's record by winning his third straight Vezina Trophy and led the league with four shutouts.

Playoffs

The top four teams qualified for the playoffs, with the first-place team facing the third-place team and the second-place team meeting the fourth-place team in best-of-seven semifinals; the winners advanced to a best-of-seven Stanley Cup Finals. Montreal, first with 61 points, faced Chicago, third with 53 points; this was their seventh playoff meeting, with the series split 3–3 previously. Montreal had won the 1944 Stanley Cup Finals in four games and took eleven of twenty points in the regular-season series.

Boston, second with 56 points, played Detroit, fourth with 50 points; this was their fifth playoff meeting, with Detroit winning three of the previous four. Detroit had won the previous year's semifinals in seven games, but Boston earned eleven of twenty points in the regular season. This was the fifth playoff meeting between Montreal and Boston, with the series split 2–2; Boston won the 1943 semifinals in five games, but Montreal took eleven of twenty regular-season points.