Jo-Carroll Dennison spent a rootless childhood in a traveling medicine show in the 1920s and ’30s with little money or formal education. She hoped to become a secretary.

But out of the blue one day in 1942, when she was 18 and walking down the street in Tyler, Texas, she was approached by a local banker who asked her to represent his bank in the town’s beauty contest. She reluctantly agreed. She won and went on to win a string of contests that culminated with her being crowned Miss America. And her life took off on an unexpected trajectory.

With World War II raging, she visited military bases on the home front, sang and danced for the troops and sold war bonds. According to Stars and Stripes, the military newspaper, photos of her in Life magazine made her the G.I.s’ second most popular “pinup girl,” after Betty Grable.

And Hollywood came calling. Ms. Dennison landed small parts in numerous movies, notably in the war propaganda film “Winged Victory” (1944) and “The Jolson Story” (1946), about the entertainer Al Jolson. She appeared on television with Frank Sinatra and Ed Sullivan and in a few episodes of the series “Dick Tracy” in 1950.

While she never achieved stardom as an actress, she spent decades in the company of Hollywood royalty. Through her brief marriage to the comedian Phil Silvers, she became a regular at Gene Kelly’s Saturday night parties and song fests, where André Previn played the piano and she rubbed shoulders with Judy Garland and Gregory Peck. Writers like Ray Bradbury gave her guidance on what books to read; Leonard Bernstein took her to concerts and advised her on which recordings to buy.

But life wasn’t all glamour. She was sexually assaulted at the age of 12. She was one of the first beauty queens to refuse to wear a swimsuit during her Miss America reign, a period that she called “indentured labor.” And as a starlet who was routinely objectified by powerful men, she was constantly fending off attempts to land her on the proverbial casting couch. These experiences made her a feminist long before there was a movement to support her.

“I’m glad to have lived long enough to see how women’s fight against inequality, sexual harassment and abuse has finally come to the fore,” she said in a video she made in September for this year’s observance of the 100th anniversary of the Miss America pageant.

Ms. Dennison was 97 and the oldest former Miss America when she died on Oct. 18 at her home in Idyllwild, Calif., in the San Jacinto Mountains west of Los Angeles. Her son Peter Stoneham confirmed the death.

Over the last 45 years, while she was in and out of movies and television, in and out of Hollywood and New York, and in and out of two marriages, Ms. Dennison wrote portions of her autobiography. She finally published it herself in September. She called it “Finding My Little Red Hat” — because, as an itinerant child, she had worn a red felt hat for courage when she went to a new school and faced yet another classroom of strangers.

“There was a definite Dickensian aspect to her story,” her son said, but her life, even the hardscrabble early years, “was absolutely crammed with wonderful characters.”

Jo-Carroll Dennison was born on Dec. 16, 1923, in a men’s state prison in Arizona.

At the time, her parents owned and ran a traveling medicine show in Texas. When her mother, Elizabeth (Brownd) Dennison, was about to give birth, her father, Harry Arthur Dennison, decided he wanted his child born in California, which he viewed as more glamorous than Texas. So they started driving west. By Arizona, her mother was in labor, and they stopped in the small town of Florence. The only help they could find was the prison doctor, who delivered Jo-Carroll in the prison infirmary.

They carried on to California in what Ms. Dennison called their house car, a Model T Ford with the flat bed of a truck. She quickly became part of the medicine show, in which her parents lured people in with entertainment and then sought to sell them elixirs. As a toddler, Jo-Carroll sang, tap-danced and performed in sketches.

When she was 7, her father left, which shattered her.

After Depression-era gigs with a circus and carnival — she rode trick ponies and roped steers — she and her mother moved back to Texas, first to the tiny town of Hale Center and then to Waco, where they signed on with another medicine show. In her autobiography, Ms. Dennison wrote that when she was 12, the snake-oil salesman who ran the show sexually assaulted her.

She and her mother moved back to Hale Center, where Jo-Carroll graduated from high school in 1940. She later moved in with an aunt in Tyler, in East Texas. She had enrolled in business school to become a secretary when the banker asked her to enter the beauty contest. She had no interest in parading before the public again, but he persisted — and offered her a free bathing suit.

Once she accepted, she wrote, her competitive juices kicked in. With the stage presence she had learned from her father, she strode around in her new black-and-white swimsuit “with an attitude to kill.”

She won the Miss Tyler, Miss East Texas and Miss Texas contests in rapid succession, then hopped a train to Atlantic City to compete in the biggest pageant of all.

With her own orchestral arrangement of “Deep in the Heart of Texas” and a high-spirited performance in a cowgirl outfit that had the audience clapping along as she sang — the newspapers called her “the Texas tornado” — she took the pageant by storm. She swept the talent and swimsuit contests, and on the final night she won the crown.

In addition to entertaining the troops, her reign as Miss America called for her to appear in her swimsuit. She felt this would be demeaning, she wrote, especially in some of the low-rent venues where she was sent; she refused to do it and even cut her tour short, though this received little public notice. The rebellious Yolande Betbeze Fox, Miss America 1951, got far more attention for rejecting swimwear on her tour because the pageant was sponsored by a bathing suit company, but Ms. Dennison preceded her by almost a decade.

In Hollywood, Ms. Dennison met Mr. Silvers on the set of “Something for the Boys” (1944). They married in 1945 and divorced in 1950. (His most famous role, as Sergeant Bilko on the television series “The Phil Silvers Show,” was yet to come.)

She married the TV producer Russell C. Stoneham in 1954; they separated in the late 1970s.

In addition to her son Peter, she is survived by another son, John Stoneham, and three grandchildren.

While Ms. Dennison loved certain aspects of being Miss America, she also felt the title gave people the impression that she was an empty-headed sex object. At parties, she wrote, it “was more a stigma than an accolade.” She still smarted years later when she recalled Groucho Marx telling her, “You’re almost articulate — for a bathing beauty.”

Hers was “a #MeToo story before #Me Too,” Evan Mills, who edited Ms. Dennison’s autobiography, said in an interview, and she had to process it all in a vacuum. “She was very much on her own,” he said.

She seemed to come to terms with her title after she bought her mountain retreat in Idyllwild in 1979 and became involved in the community, including working for nearly a dozen years for a hospice program.

When she had toured military bases as Miss America, she raised morale but knew that the soldiers were cheering her as a symbol, not for anything she had done. “But when working directly with hospice,” she wrote, “I felt that I was fulfilling that purpose and using the Miss America title in a far better way.”