O'Brien's singing abilities came to the attention of entertainer and Country Music Hall of Fame member Cliffie Stone, who hired her as a regular performer on his television show Hometown Jamboree before her high school graduation. In 1954, she became a regular on The Bob Crosby Show, and stayed until shortly before the show's cancellation in 1958. She co-starred with Cary Grant and Tony Curtis in the 1959 movie Operation Petticoat.