William Cohen (born 1940) is an American author and politician who served as Secretary of Defense (1997–2001) under Bill Clinton.
William Cohen may also refer to: William W. Cohen (1874–1940), U.S. Representative from New York William Edgar Cohen (1941–2014), filmmaker William D. Cohen, associate justice of the Vermont Supreme Court William N. Cohen (1857–1938), American judge
See also William D. Cohan (born 1960), newspaper reporter Bill Coen, basketball coach Billy Coen, fictional Resident Evil character