Ernst Tillich (27 June 1910 – 16 March 1985) was a German theologian.
He survived the twelve Nazi years, but nevertheless spent much of the period in state detention, including more than three years in the concentration camp at Sachsenhausen.
Subsequently, between 1951 and 1958, Tillich led the Kampfgruppe gegen Unmenschlichkeit (KgU "Combat Group against Inhumanity"), a US funded militant campaigning anti-communist organisation, based in West Berlin, which supported resistance to the one-party dictatorship that had established itself as the German Democratic Republic in October 1949.