Karl Fritzsch (10 July 1903 – reported missing 2 May 1945), a German SS functionary during the Nazi era of 1933-1945, served as an Auschwitz concentration camp deputy- and acting-commandant.
According to Rudolf Höss, Fritzsch first suggested using poisonous gas Zyklon B for the purpose of mass murder and experimented with the first gassings himself.