Publicist Harlan Boll told The Hollywood Reporter Williams died peacefully in her sleep. The exact cause of her death was not immediately disclosed.
Williams was best known for her work in a series of aquatic-themed MGM movie musicals in the 1940s and '50s. Among her film credits are "Bathing Beauty," "Take Me Out to the Ball Game," "Easy to Love" and "Million Dollar Mermaid."
"No one had ever done a swimming movie before, so we just made it up as we went along. I ad-libbed all my own underwater movements," Williams once said.