Formed in Hamburg in 1970 by guitarist Peter Hesslein, singer John Lawton, bassist Dieter Horns, keyboardist Peter Hecht, and drummer Joachim Reitenbach, Lucifer's Friend is a German rock band who were early practitioners of heavy metal and progressive rock, also incorporating elements of jazz and fusion into their music.

Beyond heavy metal, the band has been cited as a pioneer of doom metal, helping to define both genres due to the heavy sound and dark-oriented lyrics of their debut 'Lucifer's Friend' (1971), before returning to their roots in 1981 with 'Mean Machine'.