* BannedInChina: UsefulNotes/{{Nigeria}} has banned the movie because it "portrays Nigerians as gangsters and cannibals". Nigerian immigrants in South Africa are often poor and are blamed for an increase in crime. The VoxPops segments were obtained by asking locals for their opinions on Nigerian immigrants. The cannibalism is actually inspired by the treatment of albinos in Tanzania.
* BreakthroughHit: For Creator/NeillBlomkamp.
* DuelingMovies: It was one of three films released in the fall/winter of 2009 with "Nine" in the title, causing a little confusion among the less attentive of moviegoers.
* EnforcedMethodActing:
** The South Africans participating in the VoxPops didn't realize they were being filmed about space aliens. They were asked their opinion on Nigerian immigrants, and their comments were edited to make it seem like they're complaining about the prawns.
** Obesanjo's "Holy shit!" reaction when Wikus shoots the gangster - actor Eugene Khumbanyiwa was not prepared for the strength of the air compressors that blew out the side of the shack.
* FanNickname: Christopher's son is referred to as either "C.J." or "Oliver" in most works of fandom, despite having no apparent canon name. The DVD subtitles give his name as "Little C.J." The name Oliver can actually be considered canon, as it was mentioned in [[http://mnuspreadslies.com/post.php?id=45 this post to Christopher's blog]] that he had two children, named Oliver and Sherry.
* HarpoDoesSomethingFunny: The film was almost entirely improvised. Creator/NeillBlomkamp had specific ideas for each scene, and directed the actors with timing cues for when and where certain actions were to take place, but the actual dialogue and performance for the scene was entirely improvised. They would do several takes, usually without the cameras rolling and often with several different variations on the scene, until Neill and the rest of the cast decided that they had a good approach to how the scene should specifically play out; they would then film it with that direction in mind. Neill and the rest of the actors commented in the DVD extras that Creator/SharltoCopley was the undisputed master of this trope.
* LoadsAndLoadsOfRoles: Jason Cope portrayed all of the speaking aliens, as well as providing the voice of the documentary narrator.
* NamesTheSame: Located nowhere near [[Literature/TheHungerGames the District 9 where grain and wheat are grown in Panem]].
* NetworkToTheRescue: The film's entire ''existence'' is this trope. Neill Blomkamp was Peter Jackson's choice to helm the ''Franchise/{{Halo}}'' film. When the budget of that reached $145 million, the studios canned it. Jackson then gave Blomkamp $30 million and virtual ''carte blanche'' to make a movie of his choosing.
* RealitySubtext:
** Comes from the quote "if they were from another country, maybe we would understand" in the first half. Maybe intentional, maybe not, but it's hard to deny. In May 2008, ([[{{Irony}} black]]) South Africans rioted to expel Zimbabweans (primarily) as well as Malawians and Mozambicans from the country, or hack them to death with machetes--whichever. At least two people died and many more were injured. Thousands of people left the country, while others were deported, and there's still (as there has been for decades) an underlying nationalist sentiment. So yeah, no.
** The slums used in filming were actual slums in Johannesburg, where the residents were to be moved to better government housing. [[LifeImitatesArt Some of the residents hadn't been moved out by the time filming began]].
* StarMakingRole: Creator/SharltoCopley had not acted before and was pushed on camera for the original short film. The overwhelming success of this kickstarted an acting career for him, appearing in all of Blomkamp's subsequent films as well as notable hits like ''Film/{{Maleficent}}''.
* ThrowItIn:
** When Fundisawa steps out of the vehicle into District 9 for the first time, he dives for cover. This was because he didn't know there would be gunfire, and the stuntmen began firing unexpectedly.
** Kobus's reaction to the truck flipping was actually David James' reaction to the stunt ''not'' working after about seven attempts.
* WhatCouldHaveBeen:
** Originally, Creator/NeillBlomkamp and Creator/PeterJackson were attempting to adapt ''Franchise/{{Halo}}'' into a movie. When that [[DevelopmentHell fell through]], the studio let him keep the money to [[AuteurLicense do whatever he wanted]].
** Five different endings were shot. One of them was apparently so embarrassing neither Blomkamp nor Copley will say a thing about it, with Blomkamp stating, "No one will ever see that ending." The only thing known about it at this point was that Copley got very, very dirty in the process.
** The South African Rap band Music/DieAntwoord are friends of Blomkamp and were supposed to be cast in this film but scheduling difficulties got in the way and they ended up being cast in ''Film/{{Chappie}}''. One wonders how different the film would have been, given their (somewhat) sympathetic presentation in {{Chappie}} in comparison to the utterly ruthless gangsters in ''District 9''.
** The aliens were originally designed to be hulking creatures with leathery skin and tentacled faces. They were to be played by actors in creature suits. Another idea was to have the prawn design as well, but the prawn aliens would be masters of the tentacled ones. Along the way, they decided to keep the prawn design for everyone and use CGI.
* WordOfGod: The fluid is [[spoiler:actually a nanite solution used for fixing things.]]