"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 UK, 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.