Secret chambers (synonyms: hidden room; hidden area) are any room or area that is hidden away. Often these are accessed from a hidden door. Secret chambers may contain treasure, clues, portals, or may be a hidden location like a cult lair, a library of banished books, a hideout, or something else. They are common elements in worldbuilding and are used most if not all genres and world types.

When designing a secret chamber, consider how it was constructed, who knows about its location, for what purpose was it built, and how it is hidden. Often there are clues, maps, riddles, or other elements that lead to the chamber or open it.

Secret chambers have been used in our own world to hide important and valuable items as well as people from those that would wish them harm.