Simeon Davison Fess (December 11, 1861 - December 23, 1936) was a Republican politician and educator from Ohio. He served in the United States House of Representatives and U.S. Senate.

Born near Harrod, Ohio, Fess was educated at Ohio Northern University. After graduation he taught history and law at the university as well was working in the university administration. He served as the president of Antioch College from 1907-1917. While still serving in the position, Fess was elected to the House in 1912, serving five terms. He did not seek re-election in 1922, instead running for the Senate. Fess won two terms, but lost a bid for a third term in 1934. He also served as a Republican Whip from 1929-1933 and the Chairman of the Republican National Committee from 1930-1932.