"One" is a song by American heavy metal band Metallica, released as the third and final single from the band's fourth studio album, ...And Justice for All (1988). Written by band members James Hetfield and Lars Ulrich, the song portrays a World War I soldier who is severely wounded—arms, legs and jaw blown off by a landmine, blind and unable to speak or move—begging God to take his life. In the music video, attempting to communicate with the hospital staff he jolts in his bed, spelling SOS in Morse code. Production of the song was done by the band alongside Flemming Rasmussen. The song was the band's first to chart in the U.S., reaching number 35 on the Billboard Hot 100. It was also a number one hit in Finland.

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.