Mark S. Polhemus (October 14, 1860 – November 14, 1923) nicknamed "Humpty Dumpty", was a Major League Baseball player. Polhemus started the 1887 season with Haverhill of the New England League. He hit .456 in 51 games and was then acquired by the major league Indianapolis Hoosiers. However, he hit and fielded poorly and only saw action in 20 games for the Hoosiers. Polhemus played in various other minor leagues through the 1898 season.