Rudolf Nebel (March 21, 1894 - September 18, 1978) was a spaceflight advocate active in Germany's amateur rocket group, the Verein für Raumschiffahrt (VfR - "Spaceflight Society") in the 1930s and in rebuilding German rocketry following World War II.
He was an early member of the VfR and assisted with Hermann Oberth's failed publicity stunt on behalf of the group to launch a rocket at the premiere of Fritz Lang's film Frau im Mond (Woman in the Moon).
He opposed the militarisation of rocketry, and rejected the opportunity to join the army's rocket team under Captain Walter Dornberger that was taken up by Wernher von Braun and Klaus Riedel. Von Braun later tried again during the war to have him join, but by now the SS regarded him as untrustworthy and had von Braun cease his attempts.