Myles Walter Keogh (25 March 1840 – 25 June 1876) was an Irish soldier. Serving the armies of the Papal States during the war for Italian unification in 1860, he was recruited into the Union Army during the American Civil War, serving as a cavalry officer, particularly under Brig. Gen. John Buford during the Gettysburg Campaign and the three-day Battle of Gettysburg. After the war, Keogh remained in the regular United States Army as commander of I Troop of the 7th US Cavalry Regiment under George Armstrong Custer during the Indian Wars, until he was killed along with Custer and all of his men at the Battle of the Little Bighorn in 1876.