Liev Schreiber accepted the role of the film's main antagonist, the Storm King, because he was eager to appear in a film he would be able to take his children to see, noting his repertoire of violent, adult-oriented films.
At PonyCon AU in Australia, it was stated that the film would not be related to Equestria Girls and that the production staff is "going all out on it, to make sure it doesn't just feel like an extended episode."
This is the second "My Little Pony" theatrical film in the saga's history, after My Little Pony: The Movie (1986).
This is the first feature length "My Little Pony: Friendship is Magic" film that is not part of the "Equestria Girls" series.
Describing what the movie's scope was like, Tara Strong, voice actress for Twilight Sparkle, stated in an interview, "Working on the feature was similar to working on the show, just that the stakes are higher and the adventure is bigger. We leave Equestria and find out that there are other lands. There's something that forces Twilight to have to rely on her friends to help set things right. Any time you go from a series to a feature, you have to have a big story, and they certainly accomplished that."
Songbird Serenade's design is modeled to reflect her voice actor Sia's stage persona, complete with large wigs.
This is the 3rd theatrically released traditionally animated film of the 2010s, after Winnie the Pooh (2011) and The SpongeBob Movie: Sponge Out of Water (2015).
The name "Celaeno" originates from Greek mythology, belonging to one of the Harpies (bird-like creatures).
The Seaponies in the film are inspired by the mythological creatures known as hippo-campuses, which were typically depicted as having the upper body of a horse and the lower body of a fish.
During the music panel for BABSCon 2015 in San Francisco, Daniel Ingram suggested the possibility of working with a live orchestra on the film's musical score.
Michael Peña ad-libbed much of the character's dialogue, with Meghan McCarthy saying, "You get Michael Peña in a recording booth, and you just are like, 'Please just go and say funny things.' He will be there for hours, just giving you all kinds of really great material that was not something that we had originally scripted!"
Kristin Chenoweth said that she dabbled in method acting for the role, making sure her hair was "on point for every recording session".
Liev Schreiber accepted his role as the Storm King due to having a lack of family-friendly roles in his career.
Liev Schreiber considers the Storm King to be "one of the more intense roles [he's] played".
Meghan McCarthy stated that as the film's villainous comic relief, Grubber "needed to be goofy" to counterpoint the "very straight-laced, hard core [sic]" Tempest.
Fan favorite characters the Cutie Mark Crusaders (Applebloom, Scootaloo and Sweetie Belle) appear in non-speaking cameos. Despite not having any lines, Michelle Creber got listed in the credits.
Kathleen Barr and Kelly Sheridan stated that fan favorites Trixie and Starlight Glimmer will appear as cameos only.
On the development of the character, screenwriter Meghan McCarthy said, "We just arrived at this idea of a character who had come from Equestria, and had not had the positive experience that Twilight [Sparkle] and her friends had. It felt like a good counterpart to our heroes was to have a villain who didn't just not get friendship, but had a reason that she didn't understand it."
Meghan McCarthy noted that Emily Blunt's performance was "a big influence" on how Tempest Shadow was animated in the film.
This is the second animated movie of 2017 to be based off a children's TV series. The first was The LEGO Ninjago Movie (2017), which released 2 weeks before this movie.
Tempest doesn't have a cutie mark, but her armor does have the symbol of The Storm King where one would be.
While the initial returns were considered poor from some sites, Cartoon Brew's Amidi stated that since Lionsgate is not directly in the business of releasing family-friendly films, the opening take readily exceeded the distributor's other attempts at this genre; likewise, Amidi estimated that the film had a budget between $5 to $8 million, based on budgets for films with similar styles as well as accounting for the work being done primarily in-house at Hasbro to reduce costs.