Henry Moore Harrington (April 30, 1849 – June 25, 1876) was a military officer in the U.S. 7th Cavalry Regiment who perished with George Armstrong Custer at the Battle of Little Big Horn in the Montana Territory. In 1873, Company C was reassigned to the Dakota Territory and Harrington accompanied Lieutenant Colonel (Brevet Major General) George Armstrong Custer on the 1873 Yellowstone Expedition. In 1874, he took part in the Black Hills Expedition.