The Sticker Museum is a grand museum hidden underground in Decalburg in Paper Mario: Sticker Star. At first, the door leading to it is locked. Once the Green Toad trapped under the fountain in Decalburg's plaza is rescued, he rewards Mario by opening up the Sticker Museum. This area uses a remix of the Decalburg theme. The museum is separated into two sections, one half for Thing Stickers (the blue section on the left side) and the other for Battle Stickers (the orange section on the right side).
The Sticker Museum is, at first, empty; the frames that should contain stickers are all blank. Stickers can be placed in spots via Paperization, thus completing their entry. Entries for battle stickers give a power rating, attack range, and unique description. Thing Stickers provide a view of the Thing, the thing sticker, and a description. If Mario owns any stickers in his album that are not in the museum, the section containing the sticker's location lights up. Once inside a section, a faint outline of the sticker determines where to place it. Speaking to the curator tells Mario how many stickers he has placed, and how many more he needs to place. Mario's walking speed in the Sticker Museum is slightly sped up to navigate faster.
There are 64 Thing Stickers and 96 Battle Stickers total, and completing each section unveils a new exhibit. Completing the Battle Stickers section unlocks an enemy gallery with enemy attack patterns, and completing the Thing Sticker section unlocks a music gallery. The only stickers that are not included are Kersti and the Flip-flop sticker.
The player pays one coin to view a series of enemy attack patterns through a pair of binoculars. Each enemy attacks a cardboard cutout of Mario, with the setting of each "battle" scene differing depending on the enemy, and also shows its damage and dizzy animation. The player can only view the enemies for a limited amount of time before the viewing time runs out and they must pay another coin to view again from where they left off.
In the music gallery, Mario sits on a sofa while music plays through speakers and an album cover representing the current song is displayed overhead. The songs can only be played sequentially: the player can press to skip to the next song, otherwise the song skips automatically after it has looped once.
29 of the game's songs are playable in the gallery. Song titles marked with an asterisk (*) are the titles used in the British English version of the game.