Under Secretary of the Navy

The Under Secretary of the Navy is the second-highest ranking civilian official in the United States Department of the Navy. The Under Secretary, called the "Under" in Pentagon slang, reports to the Secretary of the Navy (SECNAV).

The four Assistant Secretaries of the Navy (for Research, Development and Acquisition; Manpower and Reserve Affairs; Financial Management and Comptroller; and Installations and Environment) report to the Under Secretary, along with the General Counsel of the Department of the Navy, the Chief of Naval Operations, the Commandant of the Marine Corps, the Chief of Legislative Affairs, the Auditor General of the Navy, the Assistant for Administration, and the Director of the Office of Small Business Programs.

Robert C. Martinage is currently Acting Under Secretary.

==Under Secretaries of the Navy, 1940—Present ==