"Once Upon a Time in Springfield" is the tenth episode of the twenty-first season of the American animated television series The Simpsons. It originally aired on the Fox network in the United States on January 10, 2010. It was promoted as the 450th episode of the series, but is actually the 451st, and aired alongside The Simpsons 20th Anniversary Special – In 3-D! On Ice!. The episode is dedicated to posthumous guest star Eartha Kitt, who died December 25, 2008, over one year before the episode first aired.

Jackie Mason was an American stand-up comedian and actor.