Harnisch is a German surname. Notable people with the surname include:
Henning Harnisch (born 1968), German basketball player Klaus Harnisch (born 1933), German director Pete Harnisch (born 1966), American baseball player Rachel Harnisch (born 1973), Swiss singer Ruth Ann Harnisch (born 1950), American presenter and activist Sebastian Harnisch (born 1967), German political scientist Thomas Harnisch (born 1947), American politician and lawyer Wilhelm Harnisch, Australian chief executive