Darius Nash Couch (July 23, 1822 – February 12, 1897) was an American soldier, businessman, and naturalist. He served as a career U.S. Army officer during the Mexican-American War, the Second Seminole War, and as a general officer in the Union Army during the American Civil War. He has been described as personally courageous, very thin in build, and after Mexico of frail health.