Assistant Secretary of the Navy (ASN) is the title given to certain civilian senior officials in the United States Department of the Navy.
From 1861 to 1954, the Assistant Secretary of the Navy was the second-highest civilian office in the Department of the Navy (reporting to the United States Secretary of the Navy). That role has since been supplanted by the office of Under Secretary of the Navy and the office of Assistant Secretary of the Navy has been abolished. There have, however, been a number of offices bearing the phrase "Assistant Secretary of the Navy" in their title (see below for details).
At present, there are four Assistant Secretaries of the Navy, each of whom reports to and assists the Secretary of the Navy and the Under Secretary of the Navy:
- Assistant Secretary of the Navy (Research, Development and Acquisition)
- Assistant Secretary of the Navy (Manpower and Reserve Affairs)
- Assistant Secretary of the Navy (Financial Management and Comptroller)
- Assistant Secretary of the Navy (Energy, Installations and Environment)
- The General Counsel of the Navy is equivalent in rank to the four Assistant Secretaries.