Springfield is the primary fictional setting of the American animated sitcom The Simpsons and related media. It is an average-sized, fictional city in an unknown state in the United States. The fictional city's geography, surroundings, and layout are flexible, often changing to accommodate the plot of any given episode.

Springfield was inspired by a number of real-life locations, including creator Matt Groening's hometown of Portland, Oregon, the nearby town of Springfield, Oregon, and producer Mike Scully's hometown of Springfield, Massachusetts. However, in order to emphasize it as an example of "Anytown, USA", the location of the fictional Springfield remains a mystery. "Clues" regarding Springfield's climate, geology, history, distance from real cities, or political alignment, which are found in numerous episodes of the series, are intentionally contradictory.

The fictional city of Springfield was intended to represent "Anytown, USA", and not be derived from any specific real-life location. However, the producers acknowledge deriving inspiration from numerous locations, including The Simpsons creator Matt Groening's hometown of Portland, Oregon, and Mike Scully's hometown, Springfield, Massachusetts.

Springfield was named after Springfield, Oregon, which, as a child, Groening had believed to be the fictitious Springfield featured in the 1950s sitcom Father Knows Best. Groening did not intend to place the fictional Springfield in Oregon, contrary to a 2012 interview with him in Smithsonian magazine; he instead adopted the name for the setting of The Simpsons in the hope that "everyone will think it's their Springfield." Al Jean explained that the magazine "misinterpreted something I've heard him say for at least 10 or 20 years. He was inspired by growing up in Portland, but it's really an every town".

Groening liked Second City Television's setting of Melonville, a town with a large cast of recurring characters, and used it as inspiration for The Simpsons. He said, "I also figured out that Springfield was one of the most common names for a city in the U.S. In anticipation of the show's success, I thought, 'This will be cool; everyone will think it's their Springfield.' And they do".

"The true location of Springfield is in any state but yours"

Because of the many contradictory statements made regarding Springfield in the show, the town cannot exist in a specific state. In The Simpsons Movie, Ned Flanders tells Bart that the state where Springfield is located is bordered by the states of Ohio, Nevada, Maine, and Kentucky – only Ohio and Kentucky are neighboring states in reality, and Nevada and Maine are at opposite sides of the US.

The fictional city's unknown geography is a recurring joke in the series; the Dayton Daily News called it the "riddle wrapped in an enigma that is Springfield's location." Episodes frequently make fun of the fact that Springfield's state is unidentifiable, by adding further conflicting descriptions, obscuring onscreen map representations, and interrupting conversational references.