Minnie Mouse is the queen of Disney Castle, who rules the peaceful kingdom alongside King Mickey. Her first appearance was in Disney's Plane Crazy. Despite being a queen, she rules the kingdom with equality to her citizens and shows no pride to her royal status. However, she has not bore Mickey an heir or heiress to his kingdom yet due to his constant quests and voyages.
Queen Minnie is very humble, regards herself as equal to her citizens, and displays very little hubris toward her status as queen. For example, she asks Aqua to address her simply as "Minnie". She cares very much for those dear to her, such as Mickey, Donald and Goofy, hoping for their safe return from their journey. Minnie also has little tolerance for evildoers, such as Pete and Maleficent, demanding to know what they are up to. The status of her kingdom also concerns her because of the Unversed and Heartless's appearances throught the years and causing chaos.
Queen Minnie is an anthropomorphized mouse with black fur and large, black, circular ears. She has long eyelashes and wears a gold tiara with a ruby Hidden Mickey-shaped symbol set in the middle. She wears an elegant ball gown with short, ball-shaped sleeves. The top of the gown is pink with red lining. The pink section sports a flower-like pattern inside circles that line the bottom. She wears another, salmon-colored layer underneath this, and a third, pleated, red layer under that. Minnie also wears white opera-length gloves that cover her whole arms and a large, red bow on the back of her dress.
Interestingly, in Kingdom Hearts, whenever Minnie turns around, her ears remain a rounded shaped so they are constantly facing the screen, just like in Disney cartoons (the same rule applies to Mickey, who also has rounded ears when he appears at the end of the game, as in the cartoons). However, in Kingdom Hearts II (and all other games afterward), their ears stay in the same position whichever way they are facing (similar to how they appear in Mickey's Twice Upon a Christmas). This is the reason why in Kingdom Hearts Queen Minnie can't be turned around like all the other characters when watched in full view in Jiminy's Journal.
Queen Minnie and Daisy Duck go over to the flowery courtyard, where they see Donald Duck fussing with Goofy about something top secret. They demand an explanation for that, so he hands over the letter he found in Pluto's mouth from King Mickey. After that, she has them follow the king's lead, worrying for all of them as well as Chip and Dale, who are the engineers for the Gummi Ship. From then on, she rules the kingdom on her own. Minnie Mouse is the one who sent Jiminy as their royal chronicler. After Ansem's defeat, Minnie is seen at Disney Castle where she and Daisy sees Huey, Dewey, and Louie returning from Traverse Town.
One year after, Queen Minnie is still ruling the world of Disney Castle on her own, with Lady Daisy as her adviser. Prior to Sora, Donald, and Goofy's visit, black rose thorns suddenly appear in the Hall of the Cornerstone, where the Cornerstone of Light is kept. Soon after Heartless begin appearing in the castle and that opens the pathway to Disney Castle. When Sora and the others visit Disney Castle, they find out that it is in danger because of Maleficent and Pete, who are threatening the castle by changing the past. Sora escorts Minnie to the king's throne, where a secret entrance lie for entering Timeless River, the castle construction site in the past. While Sora and company set off to Timeless River to prevent the past from changing, Minnie remains in the castle to protect it. After the castle is safe again, Queen Minnie continues to protect the kingdom, though it becomes the safest world throughout the game. She is reunited with King Mickey after he, Sora and the others put an end to Xemnas.
Queen Minnie is hosting the yearly Dream Festival in Disney Town. During Ventus's visit, they find themselves having trouble with the ice-cream machine that the trio received from their grand uncle, Scrooge McDuck, but Ventus manages to make it work right again. Afterwards, Aqua arrives to defeat monsters attacking the Fruit Ball Area, after which Minnie approaches to thank her. During the Rumble Race, Terra attempts to chase a group of Unversed, but almost gets crushed by Pete, who is posing as Captain Dark. Minnie warns him just in time for him to dodge the car. Then, Minnie tells him to participate in the competition as a means to help them rid of the monsters without breaking the rules.
Minnie is held hostage by Maleficent and Pete as leverage to force Mickey to hand over the Datascape to them for their plans of universal domination. However, she is rescued thanks to the unlikely appearance of Lea, who throws a chakram at Pete and distracts him long enough for Minnie to use her light spell and flee to safety to Mickey and his friends. Before she was a queen, Minnie was Princess of the Country of the Musketeers and was kidnapped by Pete in his scheme to usurp her as the ruler.
After Master Xehanort's ultimate defeat, Minnie and Daisy reunite with Mickey, Donald and Goofy at the Disney Castle. Minnie giggles at the way Mickey is tackled by Pluto and the mice reunite holding onto each other's hands. The group then watched the fireworks for the guardians of light's heroism and saving of all the other worlds.
Minnie does not have many offensive techniques, unlike the other support characters, but she can fire a light blue sphere of light, known as "Pearl", when an enemy is nearby her. These spheres are exactly like Mickey's Pearl in Kingdom Hearts II but they are blue instead of white. Together, she and Sora can use the powerful "Faith" reaction command, which temporarily banishes all Heartless in range, or defeats them if they are wounded enough. Even though she lacks power, she is strangely one of the most useful assistant characters in the game. She has also shown the ability to seal rooms in hope of keeping out unwanted visitors, like she did with the Throne Room, but the darkness found a way to seep into the room anyway, meaning her magic may not be powerful enough to completely hold back the darkness.
Minnie Mouse first appears in the 1928 short, Plane Crazy, in which she takes a ride with Mickey in a plane he built. However, because the short failed, she is better known for appearing in the 1928 short Steamboat Willie, which was the first Mickey Mouse cartoon with sound. Plane Crazy was later released with sound, the fourth cartoon, causing confusion as to which came first, and thus, which Minnie appeared in first. In Steamboat Willie, Minnie appears running to catch the steamboat, but Mickey departs on it just as she arrives. She then runs along the riverbank trying to catch the boat. Hearing Minnie's cries for help, Mickey uses the crane to pick her up. She drops her fiddle and sheet music to "Turkey in the Straw" in the process, which a goat eats. After being unable to get the music out of the goat, Mickey decides to use the goat as a phonograph, and they both dance to the music, until Pete appears, scowling. Minnie first appears in her current form in Mickey's Surprise Party in 1939. Minnie has since appeared in many Disney cartoons and films. She almost always appears with her best friend, Daisy.
- The original Minnie Mouse is not seen in Timeless River, suggesting that she wasn't present back in the early days of Disney Castle. However, it is most likely that the creators had no reason to present her in her original form, as Minnie had been created at the time of the original Steamboat Willie cartoon the world is mostly based on.
- In Kingdom Hearts, when you watch Queen Minnie in full view in the journal, you can't make her turn, unlike all the other characters.
- In real life, Minnie's English voice actress, Russi Taylor, was married to Mickey's voice actor, Wayne Allwine. Because Allwine had passed away, she was widowed until her death in 2019.
- Queen Minnie's Wedding Ring functions as the key to the Cornerstone of Light.
- In Kingdom Hearts, whenever Minnie turns around, her ears remain a rounded shaped so they are constantly facing the screen, just like in Disney cartoons (the same rule applies to Mickey, who also has rounded ears when he appears at the end of the game, as in the cartoons). However, in Kingdom Hearts II (and all other games afterward), their ears stay in the same position whichever way they are facing (similar to how they appear in Mickey's Twice Upon a Christmas).