Born in Philadelphia, the son of Frank Bettger, an infielder for the St Louis Cardinals. He left school in his late teens with the ambition of becoming an actor. Bettger graduated from the American Academy of Dramatic Arts in New York. His theatrical debut was in Brother Rat at the Biltmore Theatre in New York City in 1936. After a period languishing in small-time theatre he landed the lead role in the Broadway production of The Flying Gerardos in 1940. When Paramount sent a talent scout to see the show, Bettger was signed on a three-year contract. Bettger’s movie career began when he was cast as the lead in the film noir No Man of Her Own (1950). He soon became a regular on the set of Westerns such as Denver and Rio Grande (1952), The Great Sioux Uprising (1953), Drums Across the River (1954), Destry (1954), The Lone Ranger (1956) and Gunfight at the O.K. Corral (1957). Lyle developed a reputation for playing the bad guy and excelled in villainous roles such as the menacing Joe Beacom in Union Station (1950) and the cold-blooded Nazi Chief Officer Kirchner in The Sea Chase (1955). One of his later roles was in the 1969 film Impasse as a bigoted World War II veteran. Bettger made many appearances in dramatic roles on television, starring in the 1957 series The Court of Last Resort as well as guest starring on Hawaii Five-O, Rawhide, The Tall Man, The Rifleman, Gunsmoke, Bonanza, Blue Light, and The Time Tunnel. He was married to Mary Rolfe (1940–1996) until her death. They had three children: Lyle, Jr., Frank, and Paula. Bettger died on September 24, 2003 in Atascadero, California aged 88. His remains were cremated. He was survived by his children and a sister.