Thomas played with the Ottawa Jr. Senators in the Central Junior A Hockey League and then moved to the University of Wisconsin/ Originally a Toronto Maple Leaf, Thomas was traded to the Los Angeles Kings but was later traded to the Montreal Canadiens. He spent roughly 3 years in the AHL with the Canadiens minor league affiliate, the Nova Scotia Voyageurs. In 1977–78, Thomas was placed on waivers and claimed by the New York Rangers. Thomas continued his career with the New York Rangers for 4 more years until retiring in 1981.