Master of Puppets is the third studio album by the American heavy metal band Metallica, released on March 3, 1986, by Elektra Records. Recorded in Copenhagen, Denmark, at Sweet Silence Studios with producer Flemming Rasmussen, it is the band's final album to feature bassist Cliff Burton. While touring in support of Master of Puppets, he died on September 27, 1986 after the band's tour bus was involved in an accident in Dörarp, Sweden.

The album's artwork, designed by Metallica and Peter Mensch and painted by Don Brautigam, depicts a cemetery field of white crosses tethered to strings, manipulated by a pair of hands in a clouded, blood-red sky, with a fiery orange glow on the horizon. The album is the band’s most recent to date to feature a runtime of under an hour. Instead of releasing a single or video in advance of the album's release, Metallica embarked on a five-month American tour in support of Ozzy Osbourne. The European leg was canceled after Burton's death in September 1986, and the band returned home to audition a new bassist.

Master of Puppets peaked at number 29 on the Billboard 200 and received widespread acclaim from critics, who praised its music and political lyrics. It is widely considered to be one of the greatest and most influential metal albums of all time, and is credited with consolidating the American thrash metal scene. It was certified six times platinum by the Recording Industry Association of America (RIAA) in 2003 for shipping six million copies in the United States, and was later certified six times platinum by Music Canada and platinum by the British Phonographic Industry (BPI). In 2015, Master of Puppets became the first metal recording to be selected by the Library of Congress for preservation in the National Recording Registry for being "culturally, historically, or aesthetically significant." In 2023, guitarist Kirk Hammett ranked Master of Puppets as his favorite Metallica album.