Heinz Barwich (22 July 1911 in Berlin – 10 April 1966 in Cologne) was a German nuclear physicist. He was deputy director of the Siemens Research Laboratory II in Berlin. At the close of World War II, he went to the Soviet Union for ten years to work on the Soviet atomic bomb project, for which he received a Stalin Prize. He was director of the Zentralinstitut für Kernforschung (Central Institute for Nuclear Research) at Rossendorf near Dresden, and he was director of the Joint Institute for Nuclear Research in Dubna, Russia. For a few years, he was an agent-in-place in Russia for a Western intelligence agency, and he defected to the West in 1964.