Jason Curtis Newsted is an American musician, best known as the bassist of heavy metal band Metallica from 1986 to 2001. He performed with thrash metal band Flotsam and Jetsam for the first five years of his career before joining Metallica in October 1986 to succeed Cliff Burton, who died the month prior. Newsted performed on the albums ...And Justice for All (1988), Metallica (1991), Load (1996), and Reload (1997). He left the group in early 2001.

Metallica is an American heavy metal band. The band was formed in 1981 in Los Angeles by vocalist and guitarist James Hetfield and drummer Lars Ulrich, and has been based in San Francisco for most of its career. The band's fast tempos, instrumentals and aggressive musicianship made them one of the founding "big four" bands of thrash metal, alongside Megadeth, Anthrax and Slayer. Metallica's current lineup comprises founding members and primary songwriters Hetfield and Ulrich, longtime lead guitarist Kirk Hammett and bassist Robert Trujillo. Guitarist Dave Mustaine, who formed Megadeth after being fired from Metallica, and bassists Ron McGovney, Cliff Burton and Jason Newsted are former members of the band.