List of Stanley Cup Final sweeps

Since the Stanley Cup Final expanded to a best-of-seven format in 1939, there have been 20 sweeps in which the Stanley Cup champion won four straight games and losing none. The first 4–0 sweep is credited to the Boston Bruins who defeated the Detroit Red Wings in four straight games in the 1941 Stanley Cup Final.

Source: Wikipedia — List of Stanley Cup Final sweeps (CC BY-SA 4.0)