Judy Garland had been intended for the main part by Nunnally Johnson, but proving unreliable he picked then barely known Joanne Woodward and imposed her on the studio executives.
Orson Welles was courted for the part of Dr. Luther, played in the movie by Lee J. Cobb, but opted instead to direct Touch of Evil. Welles even read the script and told director Nunnally Johnson that whoever played the lead would win the Oscar (Joanne Woodward did, in fact, win the Oscar).
In 1980 the British rock band Siouxsie and the Banshees recorded "Christine," a song based on the same case of multiple personality dramatized in "The Three Faces of Eve".
In a TV interview, June Allyson said that she was offered the role of Eve but her husband, Dick Powell, talked her out of it saying she would be miscast.
In her 1977 book, "I'm Eve," Christine Costner Sizemore, the real-life woman on whom the character of "Eve" was based, said that she had really had 26 multiple personalities, not just three; and that the popularity of the book and movie based on her life had only traumatized her further because Dr. Corbett Thigpen had forced her to sign over all rights to her story to him. Contrary to this statement, Dr. Corbett Thigpen made personally sure that Mrs. Sizemore was given her fair share of any and all profit from the movie, for which there is paper-trail proof for any in doubt. Furthermore, Dr. Thigpen and Mrs. Sizemore were on good terms with each other before Dr. Thigpen passed away in 1999, if he had done her wrong, that would not have been the case.
The film is based on the true case of Christine Costner Sizemore who later wrote two books about her multiple personality problem, "I'm Eve" (1977) and "A Mind of My Own" (1989).