Max Christian Theodor Steenbeck (21 March 1904 – 15 December 1981) was a German physicist who worked at the Siemens-Schuckertwerke in his early career, during which time he invented the betatron in 1934. He was taken to the Soviet Union after World War II, and he contributed to the Soviet atomic bomb project. In 1955, he returned to East Germany to continue a career in nuclear physics.