William Osser Xavier Cook (October 9, 1895 – May 5, 1986) was a Canadian professional ice hockey right winger who played for the Saskatoon Crescents of the Western Canada Hockey League (WCHL) and the New York Rangers of the National Hockey League (NHL). A prolific scorer, Cook led the WCHL in goals twice and the NHL three times. He was named an all-star seven times between the two leagues.