Captain (ground forces)

''This article refers to the Marine Corps, Army, and Air Force rank of captain. For the UNSC Navy rank, see Captain (Navy).''

Captain is the highest company-grade commissioned officer rank of the UNSC Marine Corps, UNSC Army, and UNSC Air Force; it is equal in rank to lieutenant in the UNSC Navy. In the Army and Marine Corps, they are usually placed in command of companies, or serve as staff officers in battalions. They may also serve in the battalion executive officer billet. Marine Corps, Army, and Air Force captains are ranked three pay grades lower than Navy captains and have no special command authority with respect to a ship.