A vital, virile, exciting Broadway performer, Preston was once called, "the best American actor -- with a voice like golden thunder," by Richard Burton. He decided to become an actor at age 15. After studying acting at the Pasadena Playhouse, he became a steady, dependable performer in Hollywood films from the late '30s. Preston became well-known after Cecil B. De Mille cast him as Barbara Stanwyck's gambler husband in Union Pacific (1939). He was almost strictly a second-lead actor for 20 years, finally breaking through to lead roles after becoming a star on Broadway. For his Broadway performance (his first in a musical) as ebullient con-artist Harold Hill in The Music Man he won a Tony Award; he repeated the role in the screen version (1962) and it became the work for which he is best known. Preston went on to earn another Tony Award for his performance in the 1966 musical I Do! I Do!, opposite Mary Martin. Another outstanding performance was as Julie Andrews' gay friend Toddie in Blake Edwards' Victor/Victoria (1982), a performance which earned him a Best Supporting Actor Oscar nomination.
- Dropped out of high school at age 16 to pursue acting at the Pasadena Community Playhouse.
- Served as an intelligence officer in the U.S. Army Air Force during World War II.
- Was spotted by a talent scout while performing in the play Idiot's Delight, which led to a contract with Paramount.
- Final film role was in The Last Starfighter.