!! The TV show:
* BadExportForYou: Inverted - the American [=DVDs=] suffer from terrible ClumsyCopyrightCensorship, with missing music and scenes, but the full version can be found in some foreign releases. On the German DVD sets the full original audio is included even in the English tracks on some episodes, although other episodes only have correct music on the German audio track.
* DawsonCasting: By the ''cops'' inside the show.
** As well as the students, especially in later seasons.
* YouLookFamiliar: Two prominent examples are Jason Priestly and Lochlyn (Rick) Munro, who played different characters in multiple episodes.

!! The film:
* ActorAllusion: Ice Cube's verse from "Straight Outta Compton" plays as he talks to Jenko and Schmidt.
** When planning for their party, Schmidt and Jenko jokingly wonder how they are going to get alcohol, since neither one has a fake ID, a reference to ''Film/SuperBad''.
* PlayingAgainstType: The directors of these films are best known for ''WesternAnimation/CloudyWithAChanceOfMeatballs'' and ''WesternAnimation/TheLEGOMovie''. Lampshaded by a TV spot for ''The LEGO Movie'', which played up that it was from the directors of ''21 Jump Street'' and ''Film/TwentyTwoJumpStreet'', then adding, "Neither of which have anything to do with this movie."
* TooSoon: In the audio commentary, it is mentioned that the line "Doing cocaine with Willie Nelson's horse" was originally "Doing cocaine with Whitney Houston's niece." This was changed because of Houston's death shortly before the editing of the movie was supposed to be finished, and at the last minute they had to call the actor to come in and dub over a new line.

!! General:
* TruthInTelevision: Whether or not it was deliberately inspired by the show, using young-looking police officers undercover as high school students has ''actually been done''. Read about the real-life example of Alex Salinas [[http://abcnews.go.com/blogs/headlines/2012/03/real-life-21-jump-street-undercover-cop-returns-to-high-school/ here]].