He played junior hockey in Manitoba from 1935-38. Reardon turned pro in 1938-39 with the Hershey Bears and Boston Bruins. In 1941 he was loaned to the Montreal Canadiens for two seasons because of wartime (World War II) regulations. He played for the senior Nanaimo Army team in 1943-44 as a member of the Canadian Army. After the was, Reardon rejoined the Bruins for two years. In 1947 he became the playing-coach of the Providence Reds. Reardon was the playing-coach of the Sydney Millionaires of the Maritime Major Hockey League in 1953-54.