Hans-Joachim Hespos (born March 13, 1938) is a German composer of avant-garde music. He was born in Emden. Since für Cello solo (written 1964), he has composed in all genres, including many pieces for unaccompanied solo instruments and theatre works. He has always remained outside of the mainstream and has never been associated with any of the many movements in postwar European music, though he did attend summer courses at Darmstadt in the 1980s. Today, Hespos is still relatively unknown in the United States.