Which team had the most penalty minutes in a single NHL season?

The Philadelphia Flyers had the most penalty minutes by an NHL team in a single season, recording 1,980 minutes during the 1975–76 regular season.

That Flyers team was famous for its intimidating, physical style, earning the nickname “Broad Street Bullies.” Yet the penalty total was not simply a sign of disorder: Philadelphia also finished 51–13–16, won the Patrick Division and Campbell Conference, and reached the Stanley Cup Final.

The team’s most notorious enforcer was Dave Schultz, who led the NHL with 472 penalty minutes in 1974–75. Philadelphia’s aggressive identity continued into 1975–76, when Schultz led the team again with 307 regular-season penalty minutes. The Flyers also set a playoff record when Schultz served 42 minutes in one game against Toronto.

This question concerns total penalty minutes by the entire team over one regular season, not an individual player’s record or a single-game total. Those categories have different answers and are frequent sources of confusion.