Darius Nash Couch was an American military officer. He was born in Putnam County, New York in 1822, and graduated from West Point in 1846. Couch saw action in the Mexican War and the Second Seminole War before retiring from the service.

Couch accepted an appointment as a Brigadier General in the United States Army at the outbreak of the Civil War. He was a divisional commander of the Army of the Potomac, and after some success in that role he was made commander of the II Corps in 1863, leading the Corps in the battles of Fredericksburg and Chancellorsville. Couch ran the Pennsylvania Militia during the Battle of Gettysburg in 1863, and later that year was sent to the Western theatre, where he spent the remainder of the war.

Couch died in New York in 1897.