The Secret of Dr. Mabuse or The Death Ray of Dr. Mabuse (German: Die Todesstrahlen des Dr. Mabuse) is a 1964 Franco-German-Italian international co-production science fiction Eurospy crime film directed by Hugo Fregonese and Victor De Santis and starring Peter van Eyck, O.E. Hasse and Yvonne Furneaux. It was a co-production between France, Italy and West Germany. The film was the last in a series of films which had revived the Weimar era character Doctor Mabuse.

The film's sets were designed by the art directors Ernst H. Albrecht and Wilhelm Vorwerg. It was shot at the Spandau Studios in Berlin.