Michael Clarence McMahon Sr. (February 1, 1915 – December 3, 1974) was a Canadian professional ice hockey player who played 57 games in the National Hockey League between 1943 and 1946.

Born in Brockville, Ontario, he played for the Montreal Canadiens and Boston Bruins.

He won the Stanley Cup in 1944 with the Montreal Canadiens.

His son Mike McMahon Jr. also played in the NHL.

This biographical article relating to a Canadian ice hockey defenceman born in the 1910s is a stub.