The MiG-21 Bis (NATO reporting name: Fishbed) is a supersonic front-line jet fighter and interceptor aircraft, designed by the Mikoyan-Gurevich Design Bureau in the Soviet Union.

Development of what would become the MiG-21 began in the early 1950s from several prototypes (Ye-1 to Ye-4). First delta wings prototype (Ye-4) made its maiden flight on June 16, 1955 and its first public appearance during the Soviet Aviation Day display at Moscow's Tushino airfield in July 1956.

The MiG-21 was the first successful Soviet aircraft combining fighter and interceptor characteristics in a single aircraft. It was a lightweight fighter, achieving Mach 2 with a relatively low-powered afterburning turbojet.

The delta wing, while excellent for a fast-climbing interceptor, meant any form of turning combat led to a rapid loss of speed. However, the light loading of the aircraft could mean that a climb rate of 235 m/s (46,250 ft/min) was possible with a combat-loaded MiG-21bis not far short of the performance of the later F-16A.

Due to its simplicity of design, ease of mastering the piloting technique and excellent indicators of speed and maneuverability, the Mig 21 is widely used in the world.