The United States Army Ordnance Corps, formerly the United States Army Ordnance Department, is a sustainment branch of the United States Army, headquartered at Fort Gregg-Adams, Virginia. The broad mission of the Ordnance Corps is to supply Army combat units with weapons and ammunition, including at times, their procurements and maintenance. Along with the Quartermaster Corps and Transportation Corps, it forms a critical component of the U.S. Army logistics system.

The U.S. Army Ordnance Corps mission is to support the development, production, acquisition, and sustainment of weapon systems, ammunition, missiles, electronics, and ground mobility materiel during peace and war to provide combat power to the U.S. Army. The officer in charge of the branch for doctrine, training, and professional development purposes is the Chief of Ordnance. The current Chief of Ordnance is Brigadier General Robin Montgomery.