Marielle Heller is longtime friends with Tom Hanks' son Colin, and met the former at a birthday party in which she pitched him the project. Heller claimed that access was fortunate because Hanks had put out the word through his agency that he wanted a break from playing real-life people and to not send him those scripts.
According to producers, and contrary to early belief, the film is not a biopic of Fred Rogers. Rather the film centers around journalist Tom Junod and his experience interviewing Rogers, and the impact it had on him.
During the TIFF post-film panel, Tom Hanks mentions how he wishes he and his son (Colin) at 3 years old watched a half hour of Mr. Rogers a week so he could learn that it is okay to be sad. Hanks feels children don't learn the importance of expressing emotions from a young age and Mr. Rogers did an excellent job explaining this
Emmy Award winner Jim Emswiller fell from a balcony around 7.30pm on October 12, 2018 during a break in filming in Mount Lebanon, Pennsylvania, authorities say. The 61-year-old Pittsburgh man died later at a hospital. Emswiller was involved in the sound production of the film. Mount Lebanon police say Emswiller fell over a brick wall on the balcony at an apartment building.
The writers said the film took so long to be made because they worked with the estate tirelessly to ensure the accuracy of the film. They were given access to the archives to ensure it was "right". "Once we found Mari it happened" they mentioned, feeling she was the final piece of the puzzle
The title of the film (A Beautiful Day In The Neighborhood) indicates that someone involved in the story may have been one of many people to suffer from what's been referred to as The Mandela Effect in which a person remembers a pop culture reference differently from how it actually occurred. The effect has caused people to believe that there is an alternate reality in which these things were the way they remember. As the trailer shows for the film, as Mister Rogers (Tom Hanks) enters the set on Mister Rogers' Neighborhood he sings, " It's a beautiful day in this neighborhood..." but a lot of people recall the words to the song being "It's a beautiful day in the neighborhood..." which would give indication that either someone in the film either doesn't know the lyrics to the song or they remember it differently (as those who suffer from The Mandela Effect have been known to do).
Director Marielle Heller said during the 2019 London Film Festival that Hanks' extended look at the camera in the restaurant scene was the first artistic decision she made on the film. The script had this down as just a moment, where you couldn't be certain if he was looking at the audience. Heller prolonged this, making sure viewers knew he's looking at you.