Springfield Penitentiary is the main prison in Springfield.
Homer was held at Springfield Penitentiary after he was framed for committing financial fraud at Ziffcorp. However, he was released a day afterwards and replaced with Artie Ziff when he chose to do the right thing and turn himself in.
Mr. Burns was also placed in the Springfield Penitentiary after it was discovered that he stole the Concert Painting, but Homer, Lenny, and Carl busted him out in order to replace Waylon Smithers. The Springfield Penitentiary was also forced to release all minor offenders due to cutbacks as a result of a major financial crisis.
Current and former inmates of Springfield Penitentiary:
- Sideshow Bob (current; he gave up killing Bart in the episode, Gone Boy)
- Walt Warren (former)
- Homer Simpson (former; twice in episode "Sex, Pies, and Idiot Scrapes" and "The Ziff Who Came To Dinner")
- Artie Ziff (current)
- Snake Jailbird (former)
- Ice Pick (current)
- Dwight Diddlehopper (current)
- Charles Montgomery Burns (former)
- Prisoner 3230 (former)
- Mona Simpson (former)
- Frank Grimes, Jr. (current)
- Fat Tony (former)
- Legs (former)
- Cecil Terwilliger (current)
- Francesca Terwilliger (current; she was somehow released during the episode, "I'm Just a Girl Who Can't Say D'oh")
- Gino Terwilliger (current)
- Dame Judith Terwilliger (current)
- Robert Terwilliger, Sr. (current)
- Louie (former)
- Johnny Tightlips (former)
- Russ Cargill (persumed)
- Groundskeeper Willie (persumed)
- Episode – "Krusty Gets Busted" (Mentioned)
- Episode – "Principal Charming"
- Episode – "Itchy & Scratchy: The Movie"
- Episode – "The Homer They Fall"
- Episode – "Brother from Another Series"
- Episode – "Marge Simpson in: "Screaming Yellow Honkers""
- Episode – "The Great Louse Detective"
- Episode – "The Ziff Who Came to Dinner"
- Episode – "I Don't Wanna Know Why the Caged Bird Sings"
- Episode – "The Burns and the Bees"
- Episode – "American History X-cellent"
- Episode – "The Bob Next Door"
- Episode – "Donnie Fatso"
- Episode – "The Ned-liest Catch" (Mentioned)
- Episode – "Blazed and Confused"
- Episode – "Teenage Mutant Milk-caused Hurdles"
- Episode – "Gone Boy"
- Episode – "The Fat Blue Line"
- Book – Chief Wiggum's Book of Crime and Punishment
- Video game – The Simpsons: Tapped Out
- Mostly Springfield Penitentiary is inspired in design by classic prisons at the turn of the 20th century. Particularly Eastern State for it's castle looks
- Also in one episode the building resembles Leavenworth prison