The Number of the Beast is the third studio album by English heavy metal band Iron Maiden. It was released on 22 March 1982 in the United Kingdom by EMI Records and in the United States by Harvest and Capitol Records. The album was their first to feature vocalist Bruce Dickinson and their last with drummer Clive Burr.

Iron Maiden are an English heavy metal band formed in Leyton, East London, in 1975 by bassist and primary songwriter Steve Harris. Although fluid in the early years of the band, the line-up for most of the band's history has consisted of Harris, lead vocalist Bruce Dickinson, drummer Nicko McBrain, and guitarists Dave Murray, Adrian Smith and Janick Gers. As pioneers of the new wave of British heavy metal movement, Iron Maiden released a series of UK and US Platinum and Gold albums, including 1980's debut album, 1981's Killers, and 1982's The Number of the Beast – its first album with Bruce Dickinson, who in 1981 replaced Paul Di'Anno as lead singer. The addition of Dickinson was a turning point in their career, establishing them as one of heavy metal's most important bands. The Number of the Beast is among the most popular heavy metal albums of all time, having sold almost 20 million copies worldwide.