Grace Kelly was a 20th century actress. She once starred in To Catch a Thief together with Cary Grant.
In an alternate timeline, when the USS Voyager was severely damaged by the Krenim, B'Elanna Torres did wrongly remember Clark Gable starring in To Catch a Thief alongside Kelly, when in fact it had been Cary Grant. Harry Kim believed, this mistake came from the identical initials of the two, C.G. (VOY: "Year of Hell")