When The Shape of Water (2017) screened at the Toronto International Film Festival in 2017, the screening was held in the Elgin Theatre. The interior scenes of the theater in the film were shot in the Elgin Theatre, so as the audience was watching the film, they were seeing the same theater on-screen that they were sitting in.
Director Guillermo del Toro said about Sally Hawkins, "Not only was she the first choice, she was the only choice. I wrote the movie for Sally. I wrote the movie for Michael [Shannon]. Sally is... I wanted the character of Elisa to be beautiful, in her own way, not in a way that is like a perfume commercial kind of way. That you could believe that this character, this woman would be sitting next to you on the bus. But at the same time she would have a luminosity, a beauty, almost magical, ethereal."
Michael Shannon was in a Chicago bar, Old Town Ale House, the moment the film won Best Picture at the 90th Academy Awards. The bar's owner waited until after the ceremony was over to post a photo to Twitter of Shannon nonchalantly sitting at the bar alone with a pint of beer while watching the broadcast on the overhead TV set.
Director Guillermo del Toro wrote lengthy backstories for each of the major characters, some of them reportedly running over forty pages long. After casting the roles, he offered them to the actors and said they could choose to utilize or ignore the backstories for their own character. The actors responded differently, with Richard Jenkins saying he ignored the backstory, stating, "The only thing that matters is what happens on screen," while Michael Stuhlbarg said he read the backstory voraciously and found it helpful in his performance.
According to an interview with the National University of Mexico TV channel, Guillermo del Toro said that if this film had flopped he would have retired from directing altogether. He stated as well that was also the case with El laberinto del fauno (2006) and El espinazo del diablo (2001), due to the deep personal nature of these projects.