John Jordan Crittenden III was an officer in the United States Army and a member of the Crittenden family, who were prominent in political and military circles throughout the 19th century. He was killed at the Battle of Little Big Horn in the Montana Territory while on temporary assignment in the 7th U.S. Cavalry under Lt. Col. George Armstrong Custer.
He was a son of American Civil War general Thomas Leonidas Crittenden and his wife, Catherine Todd. He was a grandson and namesake of former Kentucky U.S. Senator John J. Crittenden and the great-grandson of Virginia politician John Crittenden, Sr. Young Crittenden received an appointment to the United States Military Academy in 1873, but failed to graduate, leaving school in 1875. He petitioned President Ulysses S. Grant for a commission and in the autumn of that year was assigned as a second lieutenant in the 20th U.S. Infantry.
Before the Little Big Horn campaign the following year, Crittenden was temporarily assigned to Company L of the 7th Cavalry, serving under Lieutenant James Calhoun. Shortly after his 22nd birthday, he was killed during the Battle of Little Big Horn. His body was identified by a prosthetic glass eye from an earlier injury when a shotgun accidentally discharged in his face. At the specific request of his family, Crittenden was initially buried with his men on what became known as "Calhoun Hill", but his body was exhumed in 1931 and reinterred in the Custer National Cemetery immediately adjacent to the battlefield.