The Answer
Creator Matt Groening has explained that the Simpsons’ home town is named after Springfield, Oregon. However, the fictional town itself is not set in Oregon and its state remains unknown.
There are a lot of towns and cities named Springfield in the United States. We found varying numbers from different sources about exactly how many there are exactly. worldatlas.com describes Springfield as the second most common place name in the US with 41.
For a long time, the creators of The Simpsons have had fun with the ambiguity surrounding Springfield’s location.
The uncertain location of Springfield is a running gag in the series, based on the fact that 34 states in the United States have at least one community with that name; and several have more than one. Episodes frequently make fun of the fact that Springfield’s state has never been revealed, by adding further conflicting descriptions, obscuring onscreen map representations, and interrupting conversational references.
In an interview with Smithsonian Magazine in 2012, creator Matt Groening was asked about the location of Springfield. He said, “Springfield was named after Springfield, Oregon.” Since he grew up in nearby Portland, Oregon this makes a certain amount of sense.
So that settles it, Springfield is in Oregon, right? Not so fast…
Groening goes on to explain that it was deliberately named ambiguously so that “everyone will think it’s their Springfield.” When people ask him if it is based on the Springfield in their state, he tells them “Yup, that’s right.”
While it was named after Springfield, Oregon that doesn’t mean it is meant to be Springfield, Oregon.
The LA Times points out that “In “The Simpsons Movie,” Simpson family neighbor Ned Flanders tells Bart that the states bordering Springfield’s home state are Ohio, Nevada, Maine and Kentucky.” Since there isn’t a state that borders those 4 states (in our plane of existence at least), we can presume that Springfield exists in an entirely fictional location.