In the Fall of 1939 director Hal Roach gave twenty year old Carole the lead role in his science fiction film One Million B.C. Although the movie got mixed reviews the publicity Carole received made her a star. Hal Roach was so impressed with her performance that he gave her a seven year contract. Carole starred opposite John Hubbard in the comedies Turnabout and Road Show. She also appeared in Topper Returns, a sequel to the hit movie Topper. While working at the Roach studio Carole underwent a physical transformation. She lost nearly 20 pounds, dyed her hair platinum blonde, and had cosmetic surgery on her nose. In 1940 she was loaned to Paramount to star in the drama Mystery Sea Raider. Carole had brief romances with assistant director Hal Roach Jr. and agent Pat DiCicco.
She married yacht broker William Hunt on July 4, 1940 after a whirlwind romance. They divorced four months later. Frank Seltzer, Hal Roach's head of publicity, gave Carole the nickname "The Ping Girl: Because She Makes You Purr". The idea came from an automobile ad slogan that said "change ping to purr". Carole hated this nickname probably because the word "ping" was also slang for a male erection. When Hal Roach threw a party at Ciro's to introduce "The Ping Girl" Carole refused to attend. She said "I was never consulted about the scheme nor do I approve the appellation they would like to inflict upon me. For these reasons I will not be present at my own reception to ping, purr, or even coo."
Carole also asked that the newspapers not publish any more of her bathing suit pin-ups. Her protest got her a lot of attention and some critics thought it was all just a publicity stunt. In December of 1940 she left Hal Roach's studio and signed a new contract with 20th Century Fox.