Chadwick started his NHL career in the 1955–56 season by playing five games for the Toronto Maple Leafs as a replacement for injured future-hall-of-famer Harry Lumley. Over the next two seasons Chadwick would play 140 consecutive regular season games, which is still a Leafs team record. However Chadwick's success in the NHL was shortlived, as his playing time dropped off and he was shipped down to the Rochester Americans of the American Hockey League. Chadwick only managed to play four more NHL games, as a member of the Boston Bruins in 1961–62. Chadwick would play the remainder of his days in the AHL, first for the Hershey Bears, and then the Buffalo Bisons before retiring in 1968.