Random Trivia For This Title:
- The androids' names in the [Alien] films follow an alphabetical pattern: in Alien it's Ash, in Aliens and Alien³ it's Bishop, in Alien: Resurrection it's Call and in this film it's David.
- Designer H.R. Giger, who worked on the original design of the Xenomorph Alien, was brought in to assist in reverse-engineering the design of the Aliens in the film.
- Ridley Scott decided against featuring Xenomorphs (the titular Alien of the film series) in the film, as "the sequels squeezed him dry, he did very well... and no way am I going back there." Instead, this being an indirect prequel to Alien, he decided to feature a Xenomorph ancestor/parent.
- During production, Ridley Scott kept the use of computer-generated imagery as low as possible, using CGI mainly in space scenes; Scott recalled advice VFXpert [?] Douglas Trumbull gave him on the set of Blade Runner: "If you can do it live, do it live", and also claimed that practical VFX was more cost-effective than digital VFX.
- Charlize Theron found herself struggling during her action scenes due to her smoking habit, particularly the segments that required her to run through sand in boots weighing 30 pounds (14 kg).
- Ridley Scott instructed Charlize Theron to stand in corners and move in lurking movements, in order to accentuate Vickers's distant, enigmatic nature.
- In 2002, Aliens director James Cameron discussed ideas for a fifth Alien film with Ridley Scott, with the intention that Cameron would produce the film with Scott directing, and Sigourney Weaver returning to star in the lead role of Ripley. However upon discovering that 20th Century Fox were developing the crossover film AVP: Alien vs. Predator, Cameron ceased all work on the project, believing that the crossover would "kill the validity of the franchise". Though Cameron went on to state that he would never again work with the [Alien] franchise, Scott eventually ended up reworking their idea into this film.
- Charlize Theron was originally cast as Elizabeth Shaw, but had to decline the role due to scheduling conflicts. Later, another change in schedule freed Theron to do the film, thus allowing her to take the role of Meredith Vickers, as Noomi Rapace had already taken the role of Shaw.
- This is not Ian Whyte's (who plays the Last Engineer) only attachment to the Alien films. Whyte also played the Predators in AVP: Alien vs. Predator and Aliens vs. Predator: Requiem~.
- Ridley Scott stated that he was filming "the most aggressive film [he] could" by not caring about MPAA ratings, having support for such bold movement from 20th Century Fox CEO Tom Rothman, who addressed Alien fans by saying that he was "very aware of their concern", and that "they can take it that the film will not be compromised either way. So if that means that the film is R, then it'll be an R. If it's PG-13, then it'll be a PG-13, but it will not be compromised." Scott shot the film with both adult-only R and more accessible PG-13 film ratings in mind, allowing the more adult content to be cut if necessary without harming the overall presentation, given the case it was asked to be cut down. Eventually, the film was rated "R for Sci-Fi violence including some intense images, and brief language", and it was released without any demanded cuts.
- Ridley Scott initially wanted Max von Sydow for the role of Peter Weyland. However, Scott and Damon Lindelof conceived of a scene in which David the android (Michael Fassbender) would interface with Weyland while in hypersleep, and that Weyland's dream would reflect his looks as a younger man since he is obsessed with immortality. Though the scene was cut from the script and never filmed, Guy Pearce had already been cast in the role and thus underwent extensive make-up to appear elderly.
- Noomi Rapace wasn't yet born when Alien was first released.
- Shaw's final message at the end of the film closely mirrors that of Ripley's final log entry at the end of Alien. Both messages include indication of being a "final log entry", description of the fates of the ships' respective crews, and identifying themselves as the "last surviving crew member of the (Nostromo/Prometheus)".
- Gemma Arterton, Carey Mulligan, Olivia Wilde, Anne Hathaway, Abbie Cornish and Natalie Portman were considered for the role of Elizabeth Shaw. While Michelle Yeoh and Angelina Jolie were originally considered for the role of Meredith Vickers, and James Franco was considered for the role of Holloway. Ben Foster was rumored for a role.