Metallica is a Grammy Award-winning American heavy metal/thrash metal band formed in 1981 and has become one of the most commercially successful musical acts of recent decades. They are considered one of the "Big Four" pioneers of thrash metal, along with Anthrax, Slayer, and Megadeth. Metallica has sold more than 90 million records worldwide, including 57 million albums in the United States alone.

Metallica was formed in Los Angeles, California, 28 October 1981 by guitarist and vocalist James Hetfield and drummer Lars Ulrich, after both had placed classified advertisements in the publication The Recycler about forming a band. The early incarnation of the band went through a number of members, including Dave Mustaine and Ron McGovney. Metallica got its name when San Francisco-area metal promoter Ron Quintana asked Lars to help pick out a name for his new magazine promoting U.S. and British metal bands. Quintana came up with a list that included the name "Metallica," while Lars suggested "Metal Mania" and "Hesse" Lars decided to use "Metallica" for the band's name.