 Born in Thetford Mines, Quebec, Fillion is a member of Thetford Mines' and one of Quebec's most famous hockey family, being one of seven hockey playing siblings.Right winger Marcel also reached the National Hockey League, playing one game for the Boston Bruins in 1944–1945 and playing in the Eastern Hockey League, the American Hockey League and the Quebec Senior Hockey League from 1944 to 1952.Right winger Dennis played in the United States Hockey League, the Pacific Coast Hockey League, the American Hockey League, the Maritime Major Hockey League, the Quebec Senior Hockey League and the Atlantic Coast Senior League from 1948 to 1956.