The Fairly OddParents is set in the fictional city of Dimmsdale which, as revealed in the special "Fairy Idol", is located along the coast of California. The city appears to be average sized, with a downtown containing large buildings and a city hall but also containing uptown areas with residences (including the house where Timmy and his parents and godparents live) and businesses (including Timmy's school; a hospital; stores; a sports complex named the Dimmadome, named after its founder and owner; the local TV channel; and various restaurants and stores) as well as a park in the center of the city. The city also appears to have rural farmland located somewhere outside of the city. The adults in the city are notably moronic and often settle situations with things like angry mobs, but they do still form a structured and complex society capable of working as a city. In the episode "Which Witch is Which", it was revealed that Dimmsdale was founded in the 1630s after Dale Dimm managed to defeat a witch hunter who was secretly a witch named Alden Biterroot (ancestor of Denzel Crocker).
When the show needs to, it switches its location to Fairy World, the magical realm and home of the fairies which is a floating world located within the sky and colored with an abundance of pink. The fairies have a civilization like that of the humans, but with a source of power being magic, which also keeps the world afloat. A large rainbow acts as the bridge between Fairy World and the Earth. Another location sometimes seen is the city of Chincinatti, the home town of Timmy's favorite comic book superhero, the Crimson Chin. Other locations include the dark and twisted Anti-Fairy World, the dark counterpart of Fairy World where the anti-fairies live, the dull and gray metropolis of Pixies Inc., home of the pixies, and Yugopotamia, where an alien, Mark Chang, lives, who is also Timmy's friend.