"Mr Crowley" is a song by British heavy metal vocalist Ozzy Osbourne. It was first released on Osbourne's debut solo album Blizzard of Ozz in September 1980 in the United Kingdom, and then a live version of the song was released as a single in November 1980. The song was written by Osbourne, guitarist Randy Rhoads, and bass guitarist/lyricist Bob Daisley.

"Mr Crowley" is one of two singles released from the Blizzard of Ozz album, with "Crazy Train" being the first. The song was inspired by a book about Aleister Crowley which Osbourne had read and a deck of tarot cards that were found in the studio as recording of the album was commencing. Crowley was an English occultist and ceremonial magician who had founded the Thelemite religion in the early 20th century.

The video game Fallout 3 uses the lyrics to the song in its walkthrough of You Gotta Shoot 'em in the Head. The game also features a ghoul character named "Mister Crowley".

This song was also featured in the game Brütal Legend.

The song was included in Guitar Hero World Tour, along with "Crazy Train" and an in-game avatar of Ozzy himself, who becomes unlocked as a playable character upon completing both songs in the vocalist career, and was made available to download on May 31, 2011 for play in the Rock Band 3 music gaming platform in both Basic rhythm, and PRO mode.

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