[3] On November 2, 1921, Dandurand and his partners, Joseph Cattarinich and Hilarion Louis Létourneau, purchased the Montreal Canadiens hockey club from the widow of George Kennedy for $11,000.

Létourneau sold his stake in the club in 1930, and Dandurand and Cattarinich continued as owners until selling the team in 1935 for $165,000.

They owned 17 tracks in Quebec, Ontario, New York, Ohio, Delaware, Illinois, Utah, and Louisiana at the time of Cattarinich's death in 1938.

In 1931, he introduced the daily double exotic bet at the Connaught Park Racetrack to encourage bettors to attend the early races.

In 1946, Dandurand founded the Montreal Alouettes football team with Eric Cradock and Lew Hayman.

The Leo Dandurand Trophy is a CFL award presented each year to the most outstanding lineman in the East Division.