Adolf Hitler oversaw the genocide of at least 5.5 million Jews and millions of other victims.
Adolf Hitler . Under Hitler 's leadership and racially motivated ideology , the Nazi regime was responsible for the genocide of at least 5.5 million Jews and millions of other victims whom he and his followers deemed Untermenschen ( `` sub-humans '' ) and socially undesirable . The Holocaust ( from the Greek ὁλόκαυστος holókaustos : hólos , `` whole '' and kaustós , `` burnt '' ) , also referred to as the Shoah ( Hebrew : השואה , HaShoah , `` the catastrophe '' ) , was a genocide in which some six million European Jews were killed by Adolf Hitler 's Nazi Germany , and the World War II collaborators with the Nazis . The victims included 1.5 million children , and constituted about two-thirds of the nine million Jews who had resided in Continental Europe .