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.

This is the first feature length "My Little Pony: Friendship is Magic" film that is not part of the "Equestria Girls" series.

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.

Kristin Chenoweth had input in choosing the color of her character's mane.

The name "Celaeno" originates from Greek mythology, belonging to one of the Harpies (bird-like creatures).

This is only the 3rd theatrically released traditionally animated American film of the 2010s, after Winnie the Pooh (2011) and The SpongeBob Movie: Sponge Out of Water (2015).

This is the second "My Little Pony" theatrical film in the saga's history, after My Little Pony: The Movie (1986).

Songbird Serenade's design is modeled to reflect her voice actor Sia's stage persona, complete with large wigs.

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!"

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.

Discord makes a brief appearance in the film as a balloon animal Pinkie Pie makes.

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.

Liev Schreiber considers the Storm King to be "one of the more intense roles [he's] played".

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.

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.

Kathleen Barr and Kelly Sheridan stated that fan favorites Trixie and Starlight Glimmer will appear as cameos only.

Uzo Aduba voices Queen Novo, the mother of Kristen Chenoweth's character Princess Skystar. In actuality, Aduba is 13 years younger than Chenoweth.

Most reviews that the film received from critics were particularly based off of it being made from a toy line rather than actually reviewing the story and screenplay, direction, animation, characters, performances of the cast, and music. This has been criticized by audiences as being an example of critics not going deep enough in their reviews, being too prejudiced and stereotypical of certain franchises, and once again not being in the same league as audiences. Another example from 2017 is Pirates of the Caribbean: Dead Men Tell No Tales, in which the surveys that many critics made were not criticizing only the film, but were making vague retrospects on the series as a whole instead.

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."

Tempest doesn't have a cutie mark, but her armor does have the symbol of The Storm King where one would be.

Meghan McCarthy noted that Emily Blunt's performance was "a big influence" on how Tempest Shadow was animated in the film.

The film's hero (Twilight Sparkle) and villain (Tempest Shadow) both share the initials "TS".

Capper references The Wizard of Oz (1939) by saying what about the queen of lions or tigers or bears? Followed by a pony saying "oh my!"

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.

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.

Michael Pena's 4th Animated Film, after Turbo (2013), Hell and Back (2015), and The LEGO Ninjago Movie (2017).

At the beginning of the movie, "We Got the Beat" by the Go-Gos is playing, but the lyrics are changed to fit in with Equestria.

The major presence of the Seaponies is a homage to My Little Pony (1984), where the Seaponies appeared and gave crucial help to the Ponies.

The end credits are done to the style of Tempest's flashback, which was in turn an homage to an art style that pops up in the series often, specifically when someone is fantasizing.

In the movie, the Storm King holds "The Staff of Sacanas". Sacana is a Portuguese word that translates to rogue/trickster, meaning the staff is the staff of rogues/tricksters.

The Storm King's death marks the 2nd villain killed off in the My Little Pony series, though it was by his own hand.