A fictional religion, hypothetical religion, imaginary religion or invented religion refers to a fictional belief system created for the purposes of literature, film, or game. Fictional religions can be complex and inspired by or build on existing religions. Two of the better known and influential examples are the Cthulhu Mythos of H. P. Lovecraft and the religion of Middle Earth created by J. R. R. Tolkien.
Some fictional religions have gained real followers in the real world and some works of fiction have inspired new religious movements (for example, the Church of All Worlds, Jediism or Matrixism); others have been intended from the beginning as parody religions (for example, Discordianism and the Church of the Flying Spaghetti Monster).