William Haynes
William, Willie, or Billy Haynes may refer to:
- William E. Haynes, United States Representative for Ohio
- William S. Haynes, American silversmith and flute maker
- William Haynes , British swimmer
- Willie Haynes, American baseball player
- William Joseph Haynes Jr., United States federal judge
- Billy Jack Haynes, American professional wrestler
- William J. Haynes II, American lawyer, General Counsel of the U.S. Department of Defense
- William Haynes , comedian and internet personality