The Mikoyan-Gurevich MiG-21 is a supersonic fighter aircraft that was developed by the Soviet Union in the late 1950s and early 1960s. It was one of the most widely used fighter jets of the Cold War era and saw service with many countries around the world.

The MiG-21 was designed by the Mikoyan-Gurevich design bureau, which was headed by Artem Mikoyan and Mikhail Gurevich. The aircraft first flew in 1956 and entered service with the Soviet Air Force in 1959. The MiG-21 was powered by a single Tumansky R-25 turbojet engine, which gave it a top speed of over Mach 2 and a range of over 1,000 miles.

The MiG-21 was armed with a variety of weapons, including air-to-air missiles, unguided rockets, and bombs for ground attack missions. It was known for its agility and high rate of climb, which made it a formidable opponent in air-to-air combat. The aircraft was also relatively inexpensive to produce and maintain, which made it attractive to many countries looking to acquire modern fighter aircraft.

The MiG-21 saw extensive combat during the Vietnam War, where it was used by the North Vietnamese Air Force against United States forces. It also saw service in many other conflicts around the world, including the Arab-Israeli Wars, the Iran-Iraq War, and the India-Pakistan Wars. The MiG-21 remains in service with many countries to this day, although it has largely been replaced by newer aircraft such as the MiG-29 and Su-27.