The United States Marine Corps falls under the authority and direction of the Department of the Navy.
The Marine Corps is a distinct branch within the U.S. military but is a component of the Department of the Navy, similar to how the Marine Corps has both air and ground elements that work together. This means the Secretary of the Navy has oversight of the Marine Corps. The Commandant of the Marine Corps is the highest-ranking officer in the Marine Corps and reports to the Secretary of the Navy. The Marines maintain both amphibious and ground units, allowing for versatile deployment in contingency and combat operations.
