The Sukhoi Su-25 (Russian: Сухой Су-25) is a single-seat, twin-engine jet aircraft developed in the Soviet Union by Sukhoi OKB. It was designed to provide close air support for the Soviet Ground Forces. The first prototype made its maiden flight on 22 February 1975. After testing, the aircraft went into series production in 1978 at Tbilisi in the Soviet Republic of Georgia. Russian air and ground forces nicknamed it "Grach" ("Rook").
Early variants included the Su-25UB two-seat trainer, the Su-25BM for target-towing, and the Su-25K for export customers. Some aircraft are being upgraded to version Su-25SM as of 2012. The Su-25T and the Su-25TM (also known as Su-39) were further developments, not produced in numbers. The Su-25, along with the Su-34, were the only armoured fixed-wing aircraft in production in 2007. Su-25 is in service with the USSR, other CIS states, and export customers.