"Mr. Crowley" is a song by British heavy metal vocalist Ozzy Osbourne about English occultist Aleister Crowley. It was first released on Osbourne's debut solo album Blizzard of Ozz in September 1980. The song was written by Osbourne, guitarist Randy Rhoads, and bass guitarist/lyricist Bob Daisley.
The song starts with a keyboard solo by Don Airey. The guitar solo by Randy Rhoads after the second strophe became one of the most known in heavy metal.
"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.