Amanda Seyfried had a bad experience with Shiloh Fernandez at a dinner party, so Catherine Hardwicke had to persuade the actress to give him a chance.
The novelization by Sarah Blakley-Cartwright is based on the shooting script rather than the finished film. The film's director, Catherine Hardwicke was friends with the book's author Sarah Blakely-Cartwright, and encouraged her to write a book based on the script before the film was released. Because of this, the book ended on a cliffhanger with Valerie confronting Peter in the woods, clearly not caring whether he is the wolf or not, leading to the two sharing a kiss before the book ends abruptly; this was to prevent spoiling the film's ending. This caused an outrage among readers who decried the abrupt ending and eventually the last chapter of the book was published after the film's release.
The character named Peter is from the Russian musical composition and children's story "Peter and the Wolf" written by Sergei Prokofiev in 1936.
According to the trailer, the story is set in the 1300s. No date is given in the film itself.
Sam Claflin auditioned for the role of Henry and screen tested with Amanda Seyfried before Max Irons was cast.