Mayo died of pneumonia and heart failure after a long illness in a nursing facility near her home in Thousand Oaks, said family friend Alex Ben Block.
In the same year, Goldwyn promoted Mayo to leading lady, casting her as Princess Margaret in "The Princess and the Pirate," an adventure comedy co-starring Hope.
Over the next few years, she teamed up with Kaye in the "The Kid From Brooklyn," "A Song Is Born" and, most notably, "The Secret Life of Walter Mitty."
As a young star known for her ash blond hair, peaches-and-cream complexion, green eyes and curvaceous figure, Mayo caught the fancy of the sultan of Morocco, who wrote her a fan letter in which he proclaimed her to be "tangible proof of the existence of God."
Goldwyn cast Mayo against her image as the dream girl next door in "The Best Years of Our Lives." Mayo was widely praised for her first major dramatic role as the two-timing wife of Andrews, a returning war veteran, in the Oscar-winning 1946 film.
Three years later, after moving to Warner Bros., Mayo gave one of her best-remembered performances, in "White Heat," director Raoul Walsh's crime melodrama in which Mayo played the unscrupulous wife of Cagney, a mentally disturbed gang boss who alternately cuddles and slaps her.
"Jimmy was the master actor, the most dynamic star the screen ever had," Mayo told the Los Angeles Times in 1981. "His acting was so real that I was really scared half the time we were on the set."
During the 1940s and '50s, Mayo appeared in more than 40 films, including "The Girl From Jones Beach" with Ronald Reagan, "Captain Horatio Hornblower" with Gregory Peck, "The Silver Chalice" with Paul Newman, "The Flame and the Arrow" with Burt Lancaster, "Along the Great Divide" with Kirk Douglas and "Colorado Territory" with Joel McCrea.
"Virginia Mayo was one of the truly great beauties of her era, and I think that people forget what a big star she really was," said Jeanine Basinger, head of the film studies program at Wesleyan University in Middletown, Conn. "She played with all the big names of her era, in both comedies and dramas."
Basinger, author of the 1993 book "A Woman's View: How Hollywood Spoke to Women," said Mayo appeared in "films that guarantee her place in film history," including "White Heat" and "The Best Years of Our Lives." But she also "was a great foil for comedians, and that's a difficult role to play, and she did it well," Basinger said.
Born Virginia Clara Jones in St. Louis on Nov. 30, 1920, Mayo was the daughter of a newspaper reporter and his wife. She showed an early interest in show business and took drama, dance and elocution lessons at her aunt's acting school.
"I fell in love with the whole idea of being up there on stage, of wearing all those wonderful, beautiful costumes," she told The Times in 1981.
After graduating from high school in 1937, Mayo broke into show business as a dancer with the St. Louis Municipal Opera Company.
When a vaudeville act called "Pansy the Horse" came to town, the two comics who wore the horse costume asked Mayo to join them as the girl in the act. She worked as the duo's beautifully attired foil for five years, touring the country and taking her stage name, Mayo, from one of the comics.
In New York City in 1941, the act joined Eddie Cantor in his Broadway musical "Banjo Eyes."
"Mr. Cantor used to sing a song to the horse, who appeared in a dream sequence in that musical version of 'Three Men on a Horse,' " Mayo told The Times in 1944. "After that, I began to sing in the act, too, using the same number."
Showman Billy Rose caught their act and put them into the revue at his Diamond Horseshoe nightclub. "It was exciting," Mayo recalled in 1981. "I got my first chance on Broadway to really sing and dance."
Mayo was brought to the attention of Goldwyn, who signed her to a long-term contract, although her singing in movies was always dubbed by someone else.
"He guided my career so beautifully," Mayo said of Goldwyn in 1981.
"He himself was so interested in developing me as a star that he used to call me every day and say, 'I want to talk to you about what you did on the screen. I want to show you the screen test you did.' And he'd drag me into the projection room.
"He kept working on me and it did take with the public because I had a very successful career."
Mayo said her success came not only with the attention Goldwyn lavished on her but the grooming in poise, wardrobe and makeup that each actress received — something that ended with the demise of the studio system.
"Back in those days, it was very important because we were selling glamour," Mayo said. "All of the moguls — Goldwyn, Selznick, Jack Warner — knew the same thing: They were selling dreams, and that consisted of glamour."
After her movie career faded in the early 1960s, Mayo acted in stage and dinner theater productions and made only occasional appearances in movies and on television.
Mayo married O'Shea in 1947, and they remained together until his death in 1973. She is survived by their daughter, Mary Johnston; and three grandsons.
Funeral services will be private.
The family suggests that memorial donations be made in Mayo's name to the St. Louis Municipal Opera, Forest Park, St. Louis, MO 63112.