The Mikoyan-Gurevich MiG-21 (Russian: Микоян и Гуревич МиГ-21; NATO reporting name: Fishbed) is a supersonic jet fighter and interceptor aircraft, designed by the Mikoyan-Gurevich Design Bureau in the Soviet Union. Its nicknames include: Balalaika, because its planform resembles the stringed musical instrument of the same name; Ołówek, Polish for "pencil", due to the shape of its fuselage,[3] and Én bạc, meaning "Silver Swallow", in Vietnamese.

Approximately 60 countries over four continents have flown the MiG-21, and it still serves many nations six decades after its maiden flight. It made aviation records, became the most-produced supersonic jet aircraft in aviation history, the most-produced combat aircraft since the Korean War and previously the longest production run of a combat aircraft (now exceeded by both the McDonnell Douglas F-15 Eagle and General Dynamics F-16 Fighting Falcon).