Oscar Beregi, born Oszkár Beregi (Budapest, January 24, 1876 – Hollywood, October 18, 1965), was a Hungarian theater and film actor. Considered one of the most important figures of the 20th-century Hungarian stage, he was a prominent member of the National Theatre in Budapest, acclaimed for his powerful performances in classical and modern roles. His film career began in the silent era in Hungary and continued internationally after his first emigration for political reasons. His most internationally famous role was as Doctor Baum in Fritz Lang's masterpiece, *The Testament of Dr. Mabuse* (1933). Upon returning to his homeland, he continued to work with enormous success, consolidating his reputation. For his outstanding artistic contributions, in 1948 he was awarded the prestigious Kossuth Prize, Hungary's highest cultural honor. After World War II, he permanently moved to the United States, where he lived until his death. He was the father of actor Oscar Beregi Jr.