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 season premiered with an episode written by guest writers Seth Rogen and Evan Goldberg.

[48] It also featured the final episode written by Daniel Chun before he left to join the American version of the television series The Office.

[50] As part of the celebration, documentary filmmaker Morgan Spurlock directed and produced The Simpsons 20th Anniversary Special – In 3-D!

[57] TV Fanatic called the season "great" while reviewing "Judge Me Tender",[58] while Emily St. James of The A.V.

"[59] "The Squirt and the Whale" was also praised for its chalkboard gag, which made a reference to the controversial South Park episodes "200" and "201",[60][61] while "To Surveil with Love" was considered the "best episode in years" by Sharon Knolle of TV Squad[62] and "one of the better outings" by Ariel Ponywether of FireFox News.

[65] The following episode, "Million Dollar Maybe", was the least viewed and lowest rated, watched by an estimated 5.110 million households and receiving a Nielsen rating of 2.4/6 in the 18-49 demographic, although this was largely down to the fact that it aired against the 2010 Grammy Awards on CBS and the 2010 Pro Bowl on ESPN.

[66] Anne Hathaway won the Emmy Award for Outstanding Voice-Over Performance for voicing Princess Penelope in "Once Upon a Time in Springfield", while Dan Castellaneta and Hank Azaria were also nominated for "Thursdays with Abie" and "Moe Letter Blues" respectively.

[67] "Once Upon a Time in Springfield" also received an Emmy nomination for Outstanding Animated Program, while The Simpsons 20th Anniversary Special - In 3-D!