The Fleet Commander is a senior Royal Navy post, responsible for the operation, resourcing and training of the ships, submarines and aircraft, and personnel, of the Naval Service. The Vice-Admiral incumbent is required to provide ships, submarines and aircraft ready for operations, and is based at Navy Command Headquarters.

His Majesty's Naval Service is the United Kingdom's naval warfare and maritime service. It consists of the Royal Navy, Royal Marines, Royal Fleet Auxiliary, Royal Naval Reserve, Royal Marines Reserve and Naval Careers Service. The Naval Service as a whole falls under the command of the Navy Board, which is headed by the First Sea Lord. This position is currently held by Admiral Sir Ben Key. The Defence Council delegates administration of the Naval Service to the Admiralty Board, chaired by the Secretary of State for Defence.