| The Simpsons | |
|---|---|
| Season 21 | |
 Digital purchase image featuring Mr. Burns | |
| Showrunner | Al Jean |
| No. of episodes | 23 |
| Release | |
| Original network | Fox |
| Original release | September 27, 2009 – May 23, 2010 |
| Season chronology | |
The twenty-first season of the American animated television series The Simpsons aired on Fox from September 27, 2009, to May 23, 2010. It was the first of two seasons that the show was renewed for by Fox,[1][2][3] and also the first season of the show to air entirely in high definition, season 20 having nine holdover episodes from season 19 that were in standard definition. The season was produced by Gracie Films and 20th Century Fox Television. Executive producer Al Jean remained the showrunner.
With this season, The Simpsons established itself as the longest-running American primetime television series surpassing Gunsmoke.[4]
The season received mainly positive reviews from critics, with many praising "The Squirt and the Whale", "To Surveil with Love" and "The Bob Next Door". The show moved up 16 positions in the Nielsen ratings from the previous season and received numerous award nominations, winning two — an Emmy Award for Anne Hathaway for her voicing in "Once Upon a Time in Springfield", and an Annie Award for "Treehouse of Horror XX".
- ^ "Fox announces Fall premiere dates for the 2009-2010 season". June 15, 2009. Archived from the original on July 15, 2009. Retrieved June 15, 2009.
- ^ ""Best. News. Ever. Fox renews hit animated series "The Simpsons" for two additional". FoxFlash. February 26, 2009. Archived from the original on January 30, 2011. Retrieved February 26, 2009.
- ^ "Breaking News — Exclusive: FOX Sets 2009-10 Season Finale Dates". The Futon Critic. Archived from the original on August 9, 2024. Retrieved April 10, 2010.
- ^ Keveney, Bill (September 28, 2008). "'The Simpsons' Hits a Landmark". ABC. Archived from the original on October 2, 2008. Retrieved October 2, 2008.