The Osaka Guard District (大阪警備府, Osaka Keibifu) was a major navy base for the Imperial Japanese Navy in central Japan during World War II.
Located at Osaka 34°42′04″N 135°27′50″E / 34.701°N 135.464°E / 34.701; 135.464), Osaka Guard District was responsible for guarding the approach to the old capital of Kyoto, the Kansai industrial zone, port of Kobe and the Inland Sea of Japan.
The Guard Districts (警備府, Keibifu) were considered second tier naval bases, similar to the first tier Naval Districts (鎮守府), with docking, fueling and resupply facilities, but typically lacked a shipyard or training school.
They tended to be established by strategic waterways or major port cities for defensive purposes.
the Guard District maintained a small garrison force of ships and Naval Land Forces which reported directly to the Guard District commander, and hosted detachments of the numbered fleets on a temporary assignment basis.