Esther Williams, a teenage swimming champion who became an enormous Hollywood star in a decade of watery MGM extravaganzas, died on Thursday in Beverly Hills, Calif. She was 91.

Her death was announced by her publicist, Harlan Boll.

From “Bathing Beauty” in 1944 to “Jupiter’s Darling” in 1955, Ms. Williams swam in Technicolor pools, lakes, lagoons and oceans, cresting onto the list of Top 10 box-office stars in 1949 and 1950.

“Esther Williams had one contribution to make to movies — her magnificent athletic body,” the film critic Pauline Kael wrote. “And for over 10 years MGM made the most of it, keeping her in clinging, wet bathing suits and hoping the audience would shiver.”

In her autobiography, “The Million Dollar Mermaid” (1999), Ms. Williams spoke of movie stardom as her “consolation prize,” won instead of the Olympic gold medal for which she had yearned. At the national championships in 1939, Ms. Williams, who was 17, won three gold medals and earned a place on the 1940 United States Olympic team. But Hitler invaded Poland, and the 1940 Olympics were canceled with the onset of World War II.