He made his stage debut at age 17 and appeared in a film the following year. He later starred in many Hollywood silents and early talkies; in Howard Hughes' Hell's Angels (1930), he piloted his own plane and shot some of the airborne scenes. Lyon married actress Bebe Daniels in 1930, and in the late '30s the two of them moved to England; there they became popular in vaudeville and on radio, and also appeared in a few films. During World War Two he was a pilot with the British Royal Air Force. After the War he was an executive talent director for Fox; later he headed his own London-based talent agency. According to some sources, he discovered Marilyn Monroe and gave her her screen name. After his wife died in 1971, he married actress Marian Nixon, one of his former costars, and they moved back to the U.S. In 1977 he was awarded the Order of the British Empire for his World War Two record. He was the father of actor Richard Lyon.