Metallica (also known as The Black Album) is the eponymously titled fifth studio album by American heavy metal band Metallica. It was released on August 12, 1991, through Elektra Records, received widespread critical acclaim and became the band's best selling album. Metallica produced five singles that are considered to be among the band's best-known songs: "Enter Sandman", "The Unforgiven", "Nothing Else Matters", "Wherever I May Roam", and "Sad but True". "Don't Tread on Me" was also issued to rock radio shortly after the album's release, but the song did not receive a commercial single release. The album marked a change in the band's sound from the thrash metal style of the band's previous four albums to a less harsh one. Metallica promoted the album with a series of tours. In 2003, the album was ranked number 252 on Rolling Stone's list of The 500 Greatest Albums of All Time.

The recording of Metallica was troubled; the band frequently entered conflicts with Bob Rock, the band's new producer, during production. The album debuted at number one in ten countries and spent four consecutive weeks at the top spot of the Billboard 200, making it Metallica's first album to top album charts. As of November 2014, the album has spent 328 weeks on the Billboard album chart, making it one of the ten longest running discs of all time.

Metallica is the group's best-selling album, one of the best-selling albums worldwide, and the best-selling album of the SoundScan era. The album was certified 16× platinum by the Recording Industry Association of America (RIAA) on December 13, 2012 and has sold over sixteen million copies in the United States since its release, being the first album in the SoundScan era to do so. Metallica played the album in its entirety during the 2012 European Black Album Tour.