Thomas and Twilight Sparkle's Adventures of Star Wars Episode IX is the ninth and final upcoming Thomas/MLP/Star Wars crossover to be made by Hiatt Grey. And is the sequel to Thomas and Twilight Sparkle's Adventures of Star Wars Episode VIII: The Last Jedi.
- Princess Celestia, Princess Luna, Barret Barricade, Princess Skyla, Armor Bride, Sweetie Heart, Scander, and Britney Sweet, Princess Yuna, Moon Starlight, Princess Sharon, Zeñorita Cebra, Knockout, Puffer, Dolphy, Rachel, Mighty Joe, Jenny, Pete, Kevin, Morley, Blitzer, Dile, Skarloey, Rheneas, Sir Handel, Peter Sam, Rusty, Duncan, Team Griffin/Eeveelution, The Griffin Family, Vinny Griffin, Glenn Quagmire, Cleveland Brown, Joe Swanson, Little Bear, Duck, Car, Owl, Hen, Emily, Lucy, Doug Funnie, Skeeter Valentine, Natsu Dragneel, Lucy Heartfilia, Erza Scarlet, Gray Fullbuster, Wendy Marvell, Happy, Carla, Nightstriker, Belle, Ariel, Melody, Princess Jasmine, Jenny Foxworth, Cinderella, Esmeralda, Mulan, Mushu, Cri-Kee, Pocahontas, Snow White, Princess Aurora, Alice, Judy Hopps, Nick Wilde, Joy, Sadness, Anger, Fear, Disgust, Hiro, Charlie, Victor, Kevin, Duck, Oliver, Toad, Donald and Douglas, Stepney, Ashima, Mavis, Jack, Alfie, Arthur, Murdoch, July, Selena, Breon, Alan, Optimus Prime, Bumblebee, Ironhide, Ratchet, Jazz, Sideswipe, Dino, Skids & Mudflap, the Wreckers, Wheelie, Brains, Hound, Cross-Hairs, Drift, Hot Rod, Cogman, the Dinobots, Dragonstorm, Zecora, Daring Do, Moon Dancer, Minuette, Lemon Hearts, Twinkleshine, Maud Pie, Limestone Pie, Marble Pie, Coco Pommel, Cheese Sandwich, Big McIntosh, Braeburn, Babs Seed, Princess Ember, Gabby, Coloratura, Derpy Hooves, Dinky Doo, Octavia Melody, Vinyl Scratch, Lyra Heartstrings, Bon Bon, Tempest Shadow, Grubber, Songbird Serenade, Capper, Captain Celaeno, Princess Skystar, Queen Novo, Shrek, Donkey, Princess Fiona, Gingy, Pinocchio, Big Bad Wolf, the Three Little Pigs, the Three Blind Mice, Dragon, Wilbur, Cardigan, Templeton, Joy, Aranea, Nellie, Pazu, Sheeta, The Dola Gang, Dominic Toretto, Luke Hobbs, Letty Ortiz, Roman Pierce, Tej Parker, Ramsey, Sean Boswell, Owen Shaw, Ellen Ripley, and John Rambo guest star in this film.
- Alter, Samantha and Slate, TD-1000, the Indominus Rex, Diesel 10, Splatter and Dodge, Diesel, Oliver the Vast, George, The Horrid Lorries, Sailor John, Ernie the Giant Chicken, Team Galactic (Mars, Jupiter and Saturn), New Brian, Megatron, Starscream, Shockwave, Soundwave, Barricade, The Fallen, Sentinel Prime, Lockdown, Quintessa, Alfred the Loaned B12 engine, Timothy the Ghost Engine, Gaston, Colonel Muska Commander Rourke, Helga Sinclair, Dawn Bellwether, Diamond Tiara, Silver Spoon, Starlight Glimmer, Suri Polomare, Gilda, Lightning Dust, Trixie, Queen Chrysalis, Nightmare Moon, Nightmare Rarity, King Sombra, and Daybreaker will work for Kylo Ren in this film.
- Flurry Heart will be born in this film.
- Spitfire and the Wonderbolts will make climax appearances in this film.
- The events from Ed, Edd, n Eddy vs. The Mummy: Tomb of the Dragon Emperor and Revenge of the Nightmare Family & Changling Queen will be mentioned.
- Rainbow - Songbird Serenade
- Heroes - David Bowie (when our heroes celebrate their victory)
- The Last Goodbye - Billy Boyd (for the end credits)