William Haynes

William Haynes may refer to:

• William J. Haynes, II (born 1958), American lawyer, General Counsel of the U.S. Department of Defense
• William S. Haynes, American silversmith and flute maker
• William E. Haynes (1829–1914), United States Representative for Ohio
• William Joseph Haynes, Jr. (born 1949), United States federal judge
• Billy Jack Haynes (born 1953), American professional wrestler
• William Haynes, SourceFed host