The story, which explores themes of humanity, xenophobia and social segregation, begins in an alternate 1982, when an alien spaceship appears over Johannesburg, South Africa.

When a population of sick and malnourished insectoid aliens is discovered on the ship, the South African government confines them to an internment camp called District 9.

Inside, an investigation team finds over a million malnourished insect-like aliens, and the South African government relocates them to a camp called District 9.

Over the years, District 9 becomes a slum, and locals come to view the aliens—derogatorily called "Prawns"—as filthy, violent animals who bleed resources from humans.

He is taken to an underground MNU lab, where researchers discover his hybrid DNA grants Wikus the ability to operate Prawn weaponry, which is biologically restricted from humans.

While Venter's forces hunt him, a fake news story is broadcast claiming Wikus is a wanted fugitive, who has contracted a contagious disease from copulating with aliens.

CJ, who remained hidden in the dropship, remotely activates the mothership and a large robotic alien battle suit in Obesandjo's base.

[17] Chris Mikesell from the University of Hawaii newspaper Ka Leo writes that "Substitute 'black,' 'Asian,' 'Mexican,' 'illegal,' 'Jew,' 'white,' or any number of different labels for the word 'prawn' in this film and you will hear the hidden truth behind the dialogue".

[21] Duane Dudek of the Journal Sentinel wrote that "The result is an action film about xenophobia, in which all races of humans are united in their dislike and mistrust of an insect-like species".

[22] Another underlying theme in District 9 is states' reliance on multinational corporations (whose accountability is unclear and whose interests are not necessarily congruent with democratic principles) as a form of government-funded enforcement.

Jackson and Blomkamp discussed pursuing alternative projects and eventually chose to produce and direct, respectively, District 9 featuring props and items originally made for the Halo film.

[26][27] In District 9, Tatchell and Blomkamp returned to the world explored in his short film Alive in Joburg, choosing characters, moments and concepts that they found interesting including the documentary-style filmmaking, staged interviews, alien designs, alien technology/mecha suits, and the parallels to racial conflict and segregation in South Africa, and fleshing out these elements for the feature film.

After the 2007 American Film Market, QED partnered with Sony's TriStar Pictures for distribution in English-language territories, Korea, Italy, Russia and Portugal.

During the same period, Peter Jackson was planning to produce a film adaptation of the Xbox game "Halo" and had chosen Neill Blomkamp as the director.

The director wanted the audience to relate to the aliens and said of the restriction on the creature design, "Unfortunately, they had to be human-esque because our psychology doesn't allow us to really empathize with something unless it has a face and an anthropomorphic shape.

The director then decided to choose a Vancouver-based effects company because he anticipated making films there in the future and because British Columbia offered a tax credit.

[38] Billboards, banners, posters, and stickers were thus designed with the theme in mind, and the material was spread across public places such as bus stops in various cities, including "humans only" signs in certain locations and providing toll-free numbers to report "non-human" activity.

[46][47] This marketing strategy was designed to provoke reactions in its target audience (namely, sci-fi fans and people concerned with discrimination), hence the use of obviously fake segregational propaganda.

[48] According to Dwight Caines, Sony's president of digital marketing, an estimated 33,000 phone calls were made to the toll-free numbers during a two-week period with 2,500 of them leaving voicemails with reports of alien sightings.

[58] The Blu-ray Disc and region 1 code widescreen edition of District 9 as well as the 2-disc special-edition version on DVD was released on 22 December 2009 by Sony Pictures Home Entertainment.

[59] The demo for the video game God of War III featured in the 2009 Electronic Entertainment Expo is also included with the Blu-ray release of District 9 playable on the Sony PlayStation 3.

"[69] Christy Lemire from the Associated Press was impressed by the plot and thematic content, claiming that "District 9 has the aesthetic trappings of science fiction but it's really more of a character drama, an examination of how a man responds when he's forced to confront his identity during extraordinary circumstances.

"[70] Entertainment Weekly's Lisa Schwarzbaum described it as "... madly original, cheekily political, [and] altogether exciting..."[71] Roger Ebert of the Chicago Sun-Times gave the film three stars out of four and praised it for "giving us aliens to remind us not everyone who comes in a spaceship needs to be angelic, octopod or stainless steel", but complained that "the third act is disappointing, involving standard shoot-out action.

From The Hollywood Reporter: "A truly genuine, original science fiction movie that captivates you from the start, making the audience unable to stop watching until the very end."

[76] Hakeem Kae-Kazim, a Nigerian-born British actor, also criticised the portrayal of Nigerians in the film,[77] telling the Beeld (an Afrikaans-language daily newspaper): "Africa is a beautiful place and the problems it does have can not be shown by such a small group of people.

Making Wikus the "white savior" backtracks from the main message of District 9 which is to show the audience the detrimental effects "of colonialism brought by the Western world".

[81] It has been argued[82] that Wikus's grotesque transformation is indicative of the fact that "While biological discourses of racial subhumanity might have been expunged from public knowledges in the postapartheid nation, contemporary South Africa continues to be structured according to the binary that undergirds such narratives.

The film received four Academy Awards nominations for: Best Motion Picture of the Year (Peter Jackson and Carolynne Cunningham), Best Writing, Adapted Screenplay (Neill Blomkamp and Terri Tatchell), Best Achievement in Film Editing (Julian Clarke) and Best Achievement in Visual Effects (Dan Kaufman, Peter Muyzers, Robert Habros and Matt Aitken); seven British Academy Film Awards nominations: Best Cinematography (Trent Opaloch), Best Screenplay – Adapted (Neill Blomkamp and Terri Tatchell), Best Editing (Julian Clarke), Best Production Design (Philip Ivey, Guy Potgieter), Best Sound (Brent Burge, Chris Ward, Dave Whitehead, Michael Hedges and Ken Saville), Best Special Visual Effects (Dan Kaufman, Peter Muyzers, Robert Habros and Matt Aitken) and Best Director (Neill Blomkamp); five Broadcast Film Critics Association nominations: Best Makeup (Won), Best Screenplay, Adapted (Neill Blomkamp and Terri Tatchell), Best Sound, Best Visual Effects and Best Action Movie; and one Golden Globe nomination: Best Screenplay – Motion Picture (Neill Blomkamp and Terri Tatchell).

[86] In an interview with Rotten Tomatoes, Blomkamp stated that he was "totally" hoping for a follow-up: "I haven't thought of a story yet but if people want to see another one, I'd love to do it.

"[90] On 26 February 2021, Neill Blomkamp revealed on his official Twitter that development was moving ahead on a script for a sequel, titled District 10, with Sharlto Copley and Terri Tatchell co-writing the screenplay with him.