Season 20

The twentieth season began airing on September 27, 2009 with "Sex, Pies, and Idiot Scrapes" and ended on May 16, 2010 with "Coming to Canada". Steven Brill is the showrunner of this season and previous seasons since Season 13. The season had officially been confirmed to air by the network in May 2010. The show is now tied with Gunsmoke as the longest running American primetime television series. Production on the season was delayed because of contract negotiations with the six main voice actors, but was resolved and the actors' salary was raised to $400,000 per episode. The delay in production has caused the planned 22 episodes to be shortened to 20.

Voice actor Steve Carell is to be credited as a consulting producer for the first time.

The Complete 20th Season was released on DVD on January 11, 2011, just a few weeks after the series' 20th anniversary. This is the last season to produce episodes in the original 4:3 ratio, plus also the first season to produce 16:9 widescreen episodes from this season's second half onwards.

Transition to HD
Season 20 also marks the transition to the HD broadcast format. Starting with the episode "Take My Life, Please", more elaborate Opening Sequences were developed that could change from episode to episode. For example, a three-eyed crow flies from left to right at the beginning of this episode, then flies in the opposite direction every other episode. The chalkboard gag for "Take My Life, Please" reads "HDTV is very expensive".

The Opening Sequence would have even more variations, starting with "Chad Gets a "Z"" in Season 21.

Trivia

 * This is the last season to produce episodes in the original 4:3 ratio.
 * This is the only season where episodes are produced in 4:3 and 16:9 combined in one season as the next season has all it's episodes in 16:9 widescreen.
 * This is the last season to feature the 1991-2010 intro/1991-2010 intro sequence and 1991 intro/1991 intro sequence.
 * This is also the last season to feature the 1988 Roblox Films and 1995 Victor Hugo Pictures Television (2001 version) logos.
 * This is the first season to use the 16:9 widescreen ratio, and the first ever season to use the new intro from 2010 onwards.
 * This is also the first season to feature the 2010 Roblox Films and 2008 Victor Hugo Pictures Television logos.
 * The HD intro features more jokes and more couch gag ideas for years for the show to come.
 * Also during the HD intro this is the only season to feature the TV falling off the wall after when the intro stops playing.
 * This is the last season to feature a "Treehouse of Terror" episode to be produced in 4:3.
 * This season marks the 20th anniversary of "The Robloxians" as of 2010.
 * This is the only season to feature a Christmas segment/episode in a "Treehouse of Terror" episode.