The structure of the United States Navy consists of four main bodies: the Office of the Secretary of the Navy, the Office of the Chief of Naval Operations, the operating forces (described below), and the Shore Establishment.

The chief of naval operations presides over the Navy Staff, formally known as the Office of the Chief of Naval Operations (OPNAV). The Office of the Chief of Naval Operations is a statutory organization within the executive part of the Department of the Navy, and its purpose is to furnish professional assistance to the secretary of the Navy (SECNAV) and the Chief of Naval Operations (CNO) in carrying out their responsibilities.

The OPNAV organization consists of:

Policy documents emanating from the CNO are issued in the form of OPNAV Instructions.

OPNAV is one of the three headquarters staffs in Department of the Navy mainly based at the Pentagon, with the others being the Office of the Secretary of the Navy and Headquarters Marine Corps.

The operating forces consists of nine components:

Fleets in the United States Navy take on the role of force provider; they do not carry out military operations independently, rather they train and maintain naval units that will subsequently be provided to the naval forces component of each Unified Combatant Command. While not widely publicized, groups of ships departing U.S. waters for operational missions gain a Task force type designation, almost always with the Second or Third Fleets. On entry into another numbered fleet's area of responsibility, they are redesignated as a task group from that fleet. For example, a carrier task group departing the Eastern Seaboard for the Mediterranean might start out as Task Group 20.1; on crossing the mid-Atlantic boundary between Fleet Forces Command and United States Naval Forces Europe - Naval Forces Africa, it might become ('inchop') Task Group 60.1.

The United States Navy currently has seven active numbered fleets. Various other fleets have existed, but are not currently active.