Episode Guide

Episodes

 * Key
 * In the # column:
 * The first number refers to the order it aired during the entire series.
 * The second number refers to the episode number within its season: i.e. 1506 would be the sixth episode of the fifteenth season.
 * The production code refers to the code assigned to the episode by the production team. The first two characters refer to the season the episode was made for. The first season is 7Gxx, the second is 7Fxx, the third is 8Fxx and the fourth is 9Fxx. After that, the fifth season started with 1F and continued in order until season nine (which was 5F). Starting with season ten, the production codes started with AABF, with the first letter changing for each season (i.e. BABF, CABF, etc.) The number at the end of the code is the order in which that episode was produced during that production run.

Season 21 (2009–2010)
Note: The Simpsons 20th Anniversary Special – In 3-D! On Ice!, which aired immediately following "Once Upon a Time in Springfield", was assigned production number LABF21 and technically counts as a component of the 20th production season (and of the 21st broadcast season). It does not, however, count towards the series' official animated episode count (i.e., it is not episode 452).

Ratings
The Simpsons first season was the Fox network's first TV series to rank among a season's top 30 highest-rated shows. Due to its success, the Fox network decided to switch The Simpsons timeslots in hopes that it would result in higher ratings for the lead out shows. It would move from 8:00 PM on Sunday night to the same time on Thursday where it would compete with The Cosby Show, the number one show at the time. Many of the producers were against the move, as The Simpsons had been in the top 10 while airing on Sunday and they felt the move would destroy its ratings. Ratings wise, new episodes of The Cosby Show beat The Simpsons every time during the second season and The Simpsons eventually fell out of the top 10. At the end of the season Cosby averaged as the fifth highest rated show on television while The Simpsons was 38th. The show remained in its Thursday timeslot until the sixth season.

The ratings for The Simpsons are split into two tables: The difference between the rank from season 11 to 12 is not a reflection of a huge audience gain, but rather that the show did better in terms of actual viewers in comparison with other shows.
 * Season 1–11 are ranked by households (in millions) watching the series.
 * Season 12–22 are ranked by actual viewers (in millions) watching the series.


 * Notes
 * 1) Until the 1996–1997 television season, ratings were calculated over 30 weeks from September to mid April. Episodes that aired after mid April were not part of the overall average and ranking.
 * 2) Season one had approximately 13.4 million viewing households. Season two dropped 9%, resulting in an average of approximately 12.2 million viewing households.
 * 3) Season three had an average rating of 13.0 points. For the season of 1991–1992, each point represented 921,000 viewing households, resulting in a total average of approximately 12.0 million viewing households.
 * 4) Season four had approximately 12.1 million viewing households. Season five dropped 13%, resulting in an average of approximately 10.5 million viewing households.