Betty Jaynes (born February 12, 1921) was a B-movie actress in the late 1930s to mid-1940s.
She was born in Greeneville, Tennessee but attended high school in Chicago. At the age of 15 she made a "sensational debut" with the Chicago City Opera Company in La boheme. In a Life magazine article, she said she would "quit school and consider movies." She signed a contract with MGM and began working in Hollywood on April 1, 1937. She appeared as Molly Moran in Babes in Arms in 1939, then in a series of minor parts in seven MGM movies through 1944. Her last major acting role was in 1952, in the I Love Lucy episode, "The Operetta".
Jaynes married actor and budding baritone Douglas McPhail during this time, but they divorced soon after. He committed suicide on December 6, 1944, after his career failed.