Dixon Stansbury Miles (May 4, 1804 – September 16, 1862) was a career United States Army officer who served in the Mexican-American War and the Indian Wars. He was mortally wounded as he surrendered his Union garrison in the Battle of Harpers Ferry during the American Civil War.
Miles was born in Maryland. He graduated from the United States Military Academy in 1824 and was commissioned a brevet second lieutenant in the 4th U.S. Infantry regiment, but was transferred immediately to the 7th U.S. Infantry, with which he served until 1847. He served on the western frontier and became adjutant of the 7th U.S. He was promoted to captain on June 8, 1836, and fought in the Seminole Wars in Florida from 1839 to 1842. At the start of the Mexican-American War, he received a brevet promotion to major for his "gallant and distinguished conduct" in the defense of Fort Brown, Texas. He fought in the Battle of Monterrey and the Siege of Veracruz, which he then governed as military commandant for four months. He was appointed a brevet lieutenant colonel for "gallant and meritorious conduct in the several conflicts at Monterrey, Mexico."
Miles spent the years before the Civil War on frontier duty battling Indians. In 1857 he fought against Indians along the Gila River, New Mexico, and against the Navajo in 1858. In 1859 he was promoted to colonel and commander of the 2nd U.S. Infantry, stationed at Fort Leavenworth, Kansas.