The Mirror World is a universe that exists parallel to Kirby's world in the Kirby series. It is notably known as the setting of Kirby & The Amazing Mirror but its inhabitants have made appearance in Kirby: Triple Deluxe, Team Kirby Clash Deluxe and Kirby Star Allies. They are usually dark versions of Kirby's world inhabitants with altered behaviors and backstories.
- Moonlight Mansion: a mansion located in a part of the world which seems to be in a perpetual state of night. Surrounded by a graveyard, Moonlight Mansion appears eerie on the outside, but holds many intriguing secrets on the inside.
- Cabbage Cavern: a large, purple, underground cavern. Inside, there are many confusing pathways, as well as underground water reservoirs with strong currents.
- Mustard Mountain: a seemingly harmless mountain; however, when Kirby begins to climb it, he finds out that it is actually an active volcano.
- Carrot Castle: a castle hidden away in a large forest. Inside are many long and winding corridors, as well as strong gusts of wind along the roof.
- Olive Ocean: a dark blue ocean, with many islands located on the surface and a large coral reef underneath. Its boss is Gobbler.
- Peppermint Palace: a large icy region divided into two parts: one area is an ice-covered mountain range, while the other is a palace made entirely out of ice and snow located in a secluded forest.
- Radish Ruins: ruins of an ancient culture, hidden away from the test of time. Kirby will pass through not only the ruins, but also a mountain range and field at sunset, before facing off with Meta Knight's mirror counterpart for the first time.
- Candy Constellation: Candy Constellation is located high above the skies of the mirror world, in space. This area being secluded, the only way to reach it is to find a special Warp Star in one of the other eight levels.
- Dimension Mirror: if all eight Mirror Shards are found, the mirror will become whole again, allowing Kirby to face the evil beings trying to take over the mirror world.
Dark Mind is an evil deity who conquer the mirror world before being defeated by Kirby in Kirby & The Amazing Mirror. He is never stated to be the mirror world version of any characters from Kirby's world but his two forms are very similar to Nightmare and Zero, two main antagonists in past Kirby games.
Dark Meta Knight
Dark Meta Knight is the mirror world version of Meta Knight and unlike him, he is a very malevolent and ruthless warrior that is responsible for trapping Meta Knight for the majority of Kirby & The Amazing Mirror while impersonating him, he is also the driving force behind Queen Sectonia's madness in Kirby: Triple Deluxe and comes back as a playable character in Kirby Star Allies.
Shadow Kirby is the mirror world version of Kirby and unlike him, he is not directly fighting evil and remains neutral to most of the events of Kirby & The Amazing Mirror. He however fight Kirby once where he display his ability to use Copy Abilities and during the battle against Dark Mind where he help Kirby if he loose his Master ability, showing that despite not be a hero, he still want to save his world.
Shadow Dedede is the mirror world version of King Dedede. While Dedede appears to have a very antagonistic personality, he is still a king who cares about his servants and about his world and is ready to fight for them. Shadow Dedede is described as a restless warrior who always tries to find an opponent and is even said to be progressively consumed by the darkness in his own heart. He serves a hidden boss in Kirby: Triple Deluxe.
Dark Taranza is the mirror world version of Taranza. He mind controlled Taranza in Team Kirby Clash Deluxe and used him to wreak havoc across the land with the power of the Black Mirror. One of the most interesting thing about Dark Taranza's appearance is that he is starting to look like Sectonia which seems to imply that he is slowly driven mad by the power of the mirror since Sectonia looked like Taranza before being corrupted by the Dimension Mirror and Dark Meta Knight.
King D-Mind is a creature similar to both Shadow Dedede and Dark Mind, he is the final boss of Team Kirby Clash Deluxe and appears to be the one Dark Taranza was working for.