"Enter Sandman" is a song by American heavy metal band Metallica. It is the opening track and lead single from their self-titled fifth album, released in 1991. The music was written by Kirk Hammett, James Hetfield and Lars Ulrich. Vocalist and guitarist Hetfield wrote the lyrics, which deal with the concept of a child's nightmares.

Metallica is the fifth studio album by American heavy metal band Metallica. It was released on August 12, 1991, by Elektra Records. Recording sessions took place at One on One Recording Studios in Los Angeles over an eight-month span that frequently found Metallica at odds with their new producer Bob Rock. The album marked a change in the band's music from the thrash metal style of their previous four albums to a slower, heavier, and more refined sound.