William Dennison "Denny" Clark (October 21, 1885 – May 30, 1932) was an American football player. He played for the University of Michigan from 1903 to 1905. He was blamed for Michigan's 1905 loss to the University of Chicago, which ended the Wolverines' 56-game unbeaten streak. He committed suicide at a hotel in Salem, Oregon, in 1932.