Mob Rules is the tenth studio album by English heavy metal band Black Sabbath, released in November 1981. It followed 1980's Heaven and Hell, and was the second album to feature lead singer Ronnie James Dio and the first with drummer Vinny Appice. Neither musician would appear on a Black Sabbath studio album again until the 1992 album Dehumanizer.

Black Sabbath were an English rock band formed in Birmingham in 1968 by guitarist Tony Iommi, drummer Bill Ward, bassist Geezer Butler and vocalist Ozzy Osbourne. They are often cited as pioneers of heavy metal music. The band helped define the genre with their first three albums Black Sabbath (1970), Paranoid (1970) and Master of Reality (1971). Following Osbourne's departure in 1979, the band underwent multiple line-up changes, with Iommi being the only constant member throughout their history.