The Soko J-21 Jastreb (English: Hawk), referred to as the J-1 Jastreb in some sources, is a Yugoslav single-seat, single-engine, light attack aircraft, designed by the Aeronautical Technical Institute (ATI) and Vojnotehnički Institut Beograd (VTI), in Belgrade and manufactured by SOKO in Mostar. Derived from the G-2 Galeb advanced jet trainer and light attack aircraft, it was designed in single-seat ground-attack and two-seat advanced flying / weapon training versions.