Oscar Beregi Sr. (born Beregi Oszkár, 24 January 1876 – 18 October 1965) was a Hungarian film actor. He appeared in 27 films between 1916 and 1953. He is remembered for his performance as Dr. Baum in Das Testament des Dr. Mabuse. He began life in Budapest, Hungary and passed away in Hollywood, California. He had been the dad of actor Oscar Beregi Jr.