Kingdom Hearts III is the first Kingdom Hearts game to be on a Microsoft console with the Xbox One port.

Sora's costume is a combination of his costumes from Kingdom Hearts II and Kingdom Hearts 3D: Dream Drop Distance.

The Teacup Attraction Flow was originally going to be in a first-person perspective, however, this angle gave testers motion sickness and was changed to third-person instead.

During a Square Enix Presents segment at E3 2015, Tetsuya Nomura revealed that the kingdom of Corona from Tangled was one of the first worlds to be considered for the game.

According to Tetsuya Nomura, the aesthetic and environment design for part of the Hercules-based "Olympus" world was primarily inspired by California's Yosemite National Park, despite, story-wise, taking place in Ancient Greece. This decision came about when co-director Tai Yasue had visited the real-world location.

In the Misty Stream area of the game, the player can find a wreckage of a pirate ship which appears to be the Phantom Storm boss from Kingdom Hearts II, s can be seen by the identical jaw piece.

On the game's box-art, the clock on the tower to the left of the characters actually has thirteen roman numerals instead of twelve, and they are out of order. In addition to that, the two hands on the clock are pointing to 13 and the 7, representing the 7 lights and 13 darknesses that play a major role in this game's story. The clock tower itself bears a striking resemblance to the NTT Docomo building in Shinjuku, Japan.

Spoiler:Scala Ad Caelum, the name of the game's final climactic world, means "Stairway to Heaven" in Latin.

The team behind Square Enix's Einhander helped develop the expansive Gummi Ship aspect of Kingdom Hearts III. They even included references to Einhander, including an unlockable Gummi Blueprint obtained by scanning a constellation in the Misty Stream area that greatly resembles Einhander' Endymion ship. One of Einhander's bosses, the Schwarzgeist, also cameos as a boss in Kingdom Hearts III, and a remix of Einhander 'Thermosphere' plays when the boss is fought with most Gummi ships. However, if the boss is fought with the Endymion blueprint, then the original PlayStation 1 version of the Thermosphere theme will play.

During a scene with the character Demyx, he spouts the line "Yes, Demyx time!" This may be a reference to the web-series "Demyx Time", which released in the late 2000's and followed a cosplayer dressed as Demyx going over Demyx's daily life and events inside Organization XIII.

When using the Classic Tone keyblade's Shotlock, Sora actually turns into the same exact cartoony monochrome form that he had donned when he was in the retro Timeless River world in Kingdom Hearts II. In addition, the 'portals' he comes out of and goes into during the Shotlock are extremely similar to the doorways that lead to different areas of the world that are used by the characters in Timeless River's story.

Arendelle's Boss, the giant wolf Heartless "Skoll", is named after and based on the figure of the same name in Norse (Viking) mythology. Specifically, the Vikings believed that two wolf figures, Hati and Skoll, were in constant pursuit of the Moon and Sun in order to devour the two celestial bodies, thus creating the day and the night. Skoll can also be seen trying to darken the boss arena at times in reference to Skoll successfully devouring the Sun during the Ragnarok, the end of all of the realms of the universe in Norse mythology.

Pixar were heavily involved in the creation of the Toy Box and Monstropolis worlds based on their properties. They collaborated with with Square Enix on the story, character design, and look of the worlds among other things and helped to design the Infinity Badge Keyblade. They even negotiated to have the story of Toy Box be set between Toy Story 2 & Toy Story 3. This went so far as to have Pixar suggest Andy's Room have the Starfield wallpaper instead of the iconic Cloud wallpaper, so the area can be chronologically accurate to the film series.

The game was originally going to be run on Square Enix's Luminous Engine, but due to problems that arose during development that involved the Kingdom Hearts team not getting used to the engine in enough time, the game was moved to the much more familiar Unreal Engine 4, a move that caused a delay in development.

The unique style of ending for the Spoiler:Yozora secret boss battle at the end of the ReMind DLC, where players obtain a different ending depending on if they win or lose the boss battle, was because Tetsuya Nomura and his team thought the fight was too extremely difficult and so wanted to give something to players that lost even if it did nothing for the series' canon.

Two characters,Spoiler:Roxas and Xion, were originally never going to appear in Kingdom Hearts III but Nomura decided to feature them in the story eventually due to him fearing massive fan backlash if he didn't.

The Dawn Till Dusk keyblade was a pre-order bonus in participating 7-Eleven stores in Japan, having the green and orange color scheme resembling the 7-Eleven brand. Its name also references the store's hours of operation: Dawn (7:00AM) Till Dusk (11:00PM).

However, In the U.S., it was a pre-order bonus for those who bought the game through the Amazon website. It was later made available as purchasable DLC through both the PlayStation Store and Microsoft Store.

Grand Chef, the Ratatouille keyblade in Kingdom Hearts III, has two bottles of champagne attached to its handles. While the artwork on these bottles originates from a poster briefly seen in the movie, it is more commonly associated with a controversial cancelled Ratatouille-branded wine that was intended to be sold in Costco in 2007, but was pulled before it could hit shelves due to concerns relating to underaged drinking. While the iteration in the movie shows red wine, the iteration on the wine bottle shows an olive tone of wine. The Grand Chef keyblade features both colors for the wine.

In Twilight Town, to enter the Le Grand Bistrot cooking minigames themed after the Pixar film "Ratatouille", you have to interact with a book outside the restaurant. The menu that appears before entering the restaurant features the film's main protagonist Remy emerging and standing in front of a page that features a message written in French on it. When translated to English, it reads:


This appears to be a shortened, paraphrased version of a restaurant review written by the critic Anton Ego towards the end of the original film.

In the climax of Kingdom Hearts III, Spoiler:Donald Duck uses Zettaflare, a previously unseen spell within either Kingdom Hearts or Final Fantasy, powerful enough to destroy a solar system. This made Spoiler:the irritable cartoon waterfowl the most powerful mage in the Final Fantasy franchise at the time, to the humor and ire of various players.

In Final Fantasy XVI, Spoiler:Bahamut, who after Spoiler:Donald's use of Zettaflare became the former most powerful mage in the Final Fantasy series, would use Zettaflare during its battle in the game, regaining its former title.