JMSDF Shimofusa Air Base is a military installation operated by the Japan Maritime Self-Defense Force (JMSDF), located in Matsudo, Chiba Prefecture, near the greater Tokyo metropolitan area. The base serves as a key facility for maritime patrol and anti-submarine warfare training and operations. Shimofusa is home to JMSDF aviation units equipped with fixed-wing patrol aircraft and helicopters. The base plays an important role in Japan's broader maritime defense posture, supporting missions across the surrounding coastal and oceanic regions. As a military airfield, Shimofusa Air Base is not open to commercial aviation and has no civilian passenger terminals or scheduled airline services. It operates exclusively under Japanese Self-Defense Force authority.