William Paul Joseph Haynes (March 1, 1910 in Montreal, Quebec – May 12, 1989) was a Canadian ice hockey forward.
Haynes started his National Hockey League career with the Montreal Maroons. He would also play with the Boston Bruins and Montreal Canadiens. His career lasted from 1931 to 1941. He discovered future stars Elmer Lach and Ken Reardon for the Canadiens after getting injured and being sent on a scouting tour of the West. His career ended when he was cut by Canadiens coach Dick Irvin for skipping practice in New York to attend the opera.