Cyrus Locher (March 8, 1878 - August 17, 1929) was a Democratic politician from Ohio. He served in the U.S. Senate.

Educated at Ohio Wesleyan University and Western Reserve University Law School, Locher served in various capacities as a prosecutor and public solicitor, as well as law professor in Cleveland, Ohio during the 1910s and 1920s. He was appointed to the U.S. Senate on April 5, 1928 upon the death of Senator Frank B. Willis. Locher served until December 14, 1928, having lost a bid for the nomination in a special election to fill the remainder of Willis's term.