This is a list of fleets of the Imperial Japanese Navy, the navy of the Empire of Japan.
This navy existed from 1868 to 1945, when it was replaced by the Japan Maritime Self-Defense Force.
These fleets were under the command of the Ministry of the Navy, Imperial General Headquarters or Imperial Japanese Navy General Staff.
These did not in general have any other fleets under their command.
These diagrams cover only fleets, omitting naval districts, guard districts, divisions, flotillas, squadrons, detachments, and other elements.