The 1973–74 NHL season was the 57th season of the National Hockey League. The Philadelphia Flyers won the Stanley Cup championship, the team's first. The team was the first of the post-1967 teams to win the Cup.

With owner Charles O. Finley unable to find a buyer, the league took over operation of the troubled California Golden Seals in February 1974.

The Philadelphia Flyers, who developed the nickname "Broad Street Bullies" because of their physical style of play, dethroned the Chicago Black Hawks as the West Division champions behind the dominant play of Bobby Clarke and Bernie Parent.

In the East Division, the Boston Bruins regained the top spot in the East and the league, behind an ongoing offensive juggernaut that saw Bruins' players finish 1–2–3–4 in NHL scoring (Phil Esposito, Bobby Orr, Ken Hodge and Wayne Cashman) for the second and most recent time in league history.

The playoffs began on April 9 with the first round, which was played between divisional opponents. The top teams all won their first rounds, with one mild upset, as the third-place New York Rangers defeated the second-place Montreal Canadiens, marking the third straight year that they had defeated the defending Stanley Cup champions in the first round. In the second round, the teams played an inter-divisional round to determine the finalists. The Eastern champion Boston Bruins took on the Western's second-place Chicago Black Hawks, while the Western champion Philadelphia Flyers took on the New York Rangers. Boston won its series in six games to take one Finals spot, while Philadelphia won its series against the New York Rangers in seven games to make the team's first Finals appearance. With Philadelphia defeating the NY Rangers in the semi-finals, this marked the first time a post 1967 NHL expansion team had ever won a playoff series against an Original 6 opponent. In the Finals, the Flyers won the series in six games against the Bruins to win not only the franchise's first championship but also to become the first post 1967 NHL expansion team and thus the first non 'Original 6' NHL team to win the Stanley Cup since the Montreal Maroons in 1935.^[3]

The Boston Bruins finished first in the league with 113 points. The Toronto Maple Leafs finished fourth in the East Division with 86 points. This was the thirteenth playoff meeting between these two teams with Toronto winning eight of the previous twelve series. They last met in the 1972 Stanley Cup Quarterfinals which Boston won in five games. Boston won four of the six games in this year's regular season series.

The Montreal Canadiens finished second in the East Division with 99 points. The New York Rangers finished third with 94 points. This was the eleventh playoff meeting between these two teams with the teams splitting the ten previous series. They last met in the 1972 Stanley Cup Quarterfinals which New York won in six games. Montreal won four of the six games in this year's regular season series.

The Philadelphia Flyers finished first in the West Division with 112 points. The Atlanta Flames finished fourth with 74 points. The Atlanta Flames made their first playoff appearance in their second season after entering the league in the previous year. The teams split this year's six-game regular season series.

The Chicago Black Hawks finished second in the West Division with 105 points. The Los Angeles Kings finished third in the West Division with 78 points. This was the first playoff meeting between these two teams. Chicago won this year's six-game regular season series earning eight of twelve points.

This was the fourth playoff meeting between these two teams with Boston winning all three previous series. They last met in the 1970 Stanley Cup Semifinals which Boston won in four games. Chicago won this year's five-game regular season series earning seven of ten points.

This was the first playoff meeting between these two teams. New York won this year's five-game regular season series earning six of ten points.

This was the first playoff meeting between these two teams. The Bruins made their thirteenth Finals appearance; winning in their last appearance in 1972 where they defeated the New York Rangers in six games. The Flyers made their first Finals appearance in their seventh season since entering the league in the 1967–68 NHL season. Boston won this year's five-game regular season series earning seven of ten points. The Philadelphia Flyers became the first non-Original Six team to win the Stanley Cup since 1935 and the first expansion team to do so since the league began expanding in 1967.

A new award, the Jack Adams for the best coach, was introduced for this season. The first winner was Fred Shero of the Philadelphia Flyers.

Note: GP = Games played, G = Goals, A = Assists, Pts = Points, PIM = Penalties in minutes

Source: NHL.^[4]

Note: GP = Games played; Min – Minutes Played; GA = Goals Against; GAA = Goals Against Average; W = Wins; L = Losses; T = Ties; SO = Shutouts

The following is a list of players of note who played their first NHL game in 1973–74 (listed with their first team, asterisk(*) marks debut in playoffs):

The following is a list of players of note that played their last game in the NHL in 1973–74 (listed with their last team):

NOTE: Frank Mahovlich would finish his major professional career in the World Hockey Association.