- Ability over Appearance: Graham Linehan actually wanted to avoid having a third Irish protagonist after Father Ted and Black Books but Chris O'Dowd gave such a good audition Linehan had to change his mind.
- Accent Depundent: In one episode Jen is dating a man who is almost perfect except that his name is Peter File, which in British English sounds almost exactly like "paedophile." Moss even points out that the problem wouldn't exist if they were in America (where the first vowel is a short rather than long "e").
- Acting for Two: One asian "actress" plays both female Sulu and female Spock in Douglas' homemade Star Trek porn. For bonus points, the actress, Gemma Chan, also played Ivana in a prior episode of the same series.
- The Cast Showoff: Philip Rham, who played Johann the German cannibal in "Moss and the German", was an actual professional cellist (as one could probably guess from him prominently playing the cello in The Stinger of the episode...)
- Development Hell: The hour-long Grand Finale special came as a result of none of the people from the series being on the same schedule once the fourth series wrapped, only having a small window of opportunity a few years later.
- Out of Order: Series 3's episodes were changed in broadcast order; especially noticeable when the episode resolving the series 2 cliffhanger that opened with a recap of said cliffhanger was broadcast third in the run.
- Playing Against Type: Less an acting example, more a behind-the-scenes one; Chris Morris, mainly known for extremely surreal Dead Baby Comedy like Jam and dark satire like Brass Eye, all of which mainly plays towards a cult audience, plays a rather broad and eccentric boss in a fairly light-hearted and mainstream (if still rather oddball) studio-based office comedy.
- What Could Have Been: An American version was planned and a pilot was shot, but not picked up. The biggest effect would have been Joel McHale passing up Community for it.
- Word of Saint Paul: Chris O'Dowd claims that Moss and Roy met in their first year of college, immediately became friends and then never made friends with anyone else.
- You Look Familiar: Belinda Stewart-Wilson plays both Denholm's widowed wife in season 2 and Douglas' wife in season 4.
- On a smaller note, actress Gemma Chan played both Ivana and Female Sulu/Female Spock in two separate season 4 episodes.
Trivia / The IT Crowd