William John Root (born September 6, 1959) is a Canadian retired professional ice hockey defenceman who played six seasons in the National Hockey League (NHL) with the Montreal Canadiens, Toronto Maple Leafs, St. Louis Blues and Philadelphia Flyers between 1982 and 1988. As a youth, he played in the 1972 Quebec International Pee-Wee Hockey Tournament with a minor ice hockey team from Toronto.