Megadeth is an American thrash metal band formed in Los Angeles in 1983 by vocalist/guitarist Dave Mustaine. Known for their technically complex guitar work and musicianship, Megadeth is one of the "big four" of American thrash metal along with Metallica, Anthrax and Slayer, responsible for the genre's development and popularization. Their music features complex arrangements and fast rhythm sections, dual lead guitars, and lyrical themes of war, politics,religion, death, and personal relationships.

 Megadeth has undergone multiple lineup changes throughout its 42-year career, with Mustaine being the sole consistent member of the band. The band temporarily disbanded in 2002 when Mustaine suffered an arm injury and re-established in 2004 without longtime bassist David Ellefson, who had taken legal action against Mustaine.  Ellefson settled out of court and rejoined the band in 2010, but was fired in 2021 amid allegations of sexual misconduct. Megadeth's current lineup includes Mustaine, bassist James LoMenzo, guitarist Teemu Mäntysaari and drummer Dirk Verbeuren.