Marcus Morton Robbins (July 25, 1851 – June 21, 1924) served in the United States Army during the American Indian Wars.

[1][2] Robbins served as a private in the Sixth U.S. Cavalry, fighting in the American Indian Wars On April 23, 1875, Robbins and five other soldiers snuck up behind a band of Cheyenne warriors and attacked them from the rear at the Battle at Sappa Creek in Kansas.

Richard Longstreth Tea, Frederick Platten, James Lowthers, Simpson Hornaday, and Peter W. Gardiner made up the rest of the expedition around the Cheyenne lines, and all received the Medal of Honor.

Michael Dawson and James F. Ayers also were a part of the battle, and also were awarded the Medal of Honor.

Twentieth-century commentators have questioned the role of the Sixth Cavalry at Sappa Creek, with some calling it a "massacre.