The William M. Jennings Trophy is an annual award given to the goalie(s) "having played a minimum of 25 games for the team with the fewest goals scored against it" during the regular season.
From 1946-81, the Vezina Trophy was awarded on these merits; after the Jennings Trophy was presented by the NHL Board of Governors in 1981, the Vezina was changed to an award honoring the goalie voted to be the best at his position.
Seven goalies have won the Jennings and Vezina trophies in the same season. Four have done it twice: Patrick Roy, Martin Brodeur, Ed Belfour and Dominik Hasek.
The Jennings Trophy was presented by the NHL Board of Governors to honor the late William M. Jennings, longtime governor and president of the New York Rangers and one of the greatest builders of hockey in the United States.