Million Dollar Mermaid is considered the crown jewel of Esther Williams' career, largely because, for once, MGM's writers were not called upon to find novel, far-fetched ways to get their star wet. Being the biography of a famous swimming star, the plot allowed Williams to organically spend nearly the entire running time in the water. It was also considered by many to be one of the best examples of Technicolor cinematography. "Million Dollar Mermaid" became Esther Williams' nickname at MGM after the success of this film and also became the title of her autobiography that was published in 1999. 

 

In an interview Esther Williams said that she met and spoke with Annette Kellerman before filming began, while attempting to get Kellerman's approval of Williams in the lead role. After the meeting Kellerman gave her complete approval and said she was pleased with the casting choice, though she good-naturedly complained that Williams was much prettier than her. The film that Kellerman is making when she has an accident is titled Neptune's Daughter (1914). In 1949, Williams would make a film with the same title. She nearly broke her neck diving off the 50-foot tower during the celebrated fountain sequence. In her memoir, Williams reports that no one considered whether or not the crown of her solid gold unitard would tolerate the pressure of her high dive until she was atop the tower for the filming of the scene. She decided to chance it in order to achieve the shot, and injured three vertebrae- she was in a body cast for seven months.