- Noomi Rapace as Elizabeth Shaw:
- Rapace described Shaw, an archaeologist, as a believer in God with a very strong faith, and said that, "In the middle of the movie, things happen and she changes into more of a warrior. And in the end, she's such a survivor."[5] To aid her method acting, she developed a complete backstory for Shaw,[6] and worked with a dialect coach to achieve an English accent.[7] She also asked her make-up artist to apply extra blood and sweat during filming to more accurately portray her character.[8] Rapace said, "I was out there filming for about six months and it was super-intense, my body was in so much pain sometimes but it was absolutely amazing."[9] She dismissed comparisons to the Alien franchise's Ellen Ripley.[10] Rapace came to director Ridley Scott's attention for her performance as Lisbeth Salander in the 2009 drama film The Girl with the Dragon Tattoo. She met Scott in August 2010,[11] and by January 2011 she had secured the role.[12] Actresses Anne Hathaway, Natalie Portman, Gemma Arterton, Carey Mulligan, and Abbie Cornish were all considered for the role during development.[13][14][15] Lucy Hutchinson, who was eight years old in 2012, portrays Shaw as a child.[16]
- Michael Fassbender as David:
- David is an android that acts as the ship's butler and maintenance man. It is designed to be indistinguishable from humans, and begins to develop "its own ego, insecurities, jealousy and envy."[17][18] Writer Damon Lindelof stated that the character provides a non-human perspective on the film's events, and said, "What does the movie look like from the robot's point of view? If you were to ask him, 'What do you think about all of this? What's going on? What do you think about these humans who are around you?' Wouldn't it be cool if we found a way for that robot to answer those questions?"[19] Fassbender said, "David's views on the human crew are somewhat childlike. He is jealous and arrogant because he realizes that his knowledge is all-encompassing, and therefore he is superior to the humans. David wants to be acknowledged and praised for his brilliance."[20] In developing his character, Fassbender avoided watching the android characters of Alien (1979) and Aliens (1986), and instead studied the replicants in Scott's 1982 science fiction film Blade Runner, with a focus on Sean Young's character Rachael, whose "vacancy" and longing for a soul interested him.[21] Fassbender drew further inspiration from the voice of the HAL 9000 computer in 2001: A Space Odyssey,[21] the "funny walk and economy of movement" of Olympic diver Greg Louganis,[22][23] and the performances of David Bowie in The Man Who Fell to Earth, Dirk Bogarde in The Servant, and Peter O'Toole in Lawrence of Arabia.[24] David's blond hair was modeled on that of T. E. Lawrence.[25] Scott favored Fassbender for the role; by January 2011 he was confirmed to have joined the cast,[26] despite earlier reports that his agents had sought too high a fee.[17]
- Charlize Theron as Meredith Vickers:
- Vickers is a Weyland Corporation employee who is sent to monitor the expedition.[20][27] Theron described the character as "a suit who slowly sheds [her] skin through the film,"[28] and also as "somewhat of a villain ... [who] definitely has an agenda."[29] She stated, "Vickers is pragmatic, and desperately wants to control the situation."[20] Scott wanted the character to lurk in the background of scenes watching other characters instead of being the focus. Theron said that this helped layer her character because "you're just so suspicious of her, instantly."[30] The similarities between the appearances and mannerisms of Vickers and David were intended to raise the possibility that David was based on Vickers's DNA, or that Vickers is an android herself.[31] After Theron was cast in the role, she developed three new scenes with Scott and Lindelof to expand her character.[32] Physical action scenes, some of which involved her running through sand in 30-pound (14 kg) boots, were a problem for Theron.[30] It was intended that Theron would portray Shaw, but a prior commitment to Mad Max: Fury Road prevented her involvement. When that film was delayed, she was able to rejoin Prometheus.[33] Michelle Yeoh and Angelina Jolie[12] were considered for the role.[17]
- Idris Elba as Janek:
- Janek is the captain of the Prometheus.[34] Elba described the character as "a longshoreman and a sailor" with a military background.[20][35] He said, "[Being the captain is] his life and the crew is his responsibility,"[20] and, "He's a realistic, pragmatic character. He has to get involved ... in a film with huge ideas, you need a character like this, who can go 'Wait ... why are we doing this?'"[35]
- Guy Pearce as Peter Weyland:
- Weyland is the billionaire founder and CEO of Weyland Corp.[36][37] Lindelof described him as having a massive ego and suffering from a god complex.[36] Applying the necessary prosthetics and make-up to transform Pearce into the aging Weyland took five hours, and an hour to remove it. Pearce observed elderly individuals to gain insight into the movement for his character, as he found replicating the impeded physical movement the most difficult part of the role.[38] Max von Sydow was Scott's original choice to play Weyland, but the casting of Pearce made it possible for him to portray Weyland as both an elderly character and a younger man who appeared in an earlier script draft.[39]
- Logan Marshall-Green as Charlie Holloway:
- Holloway is an archaeologist and Shaw's love interest.[40][41] Marshall-Green was cast after he was seen performing on stage "off-off-off Broadway."[41] He described Holloway as the "X Games-type scientist," and said that he liked the character's "leap-before-looking" philosophy. He also said that Holloway "doesn't want to meet his maker. He wants to stand next to his maker. He's willing to go to the edge to get that."[41] Describing the character's motivation, he said: "He goes to the extreme in everything he does, sometimes for the better, sometimes for the worse of the [Prometheus crew]. I think what drives him is the thrill of the search."[20] Marshall-Green contrasted Holloway with Shaw, and said: "She's the believer. I'm the scientist. I'm the skeptic. I'm the atheist."[42]
- Sean Harris as Fifield:
- Fifield is a geologist who has become mentally unstable after many missions.[43][44] Harris described the character as "someone who can sense when things are up. He's your audience guy, going, 'Don't go in that tunnel. We should not be doing this!'"[44] Fifield's bright red mohawk hairstyle was designed by Harris and Scott based on Scott's sketch of a man with a "severe haircut."[44]
- Rafe Spall as Millburn:
- Millburn is a biologist. Spall auditioned for another role, but Scott wanted him to play Millburn.[45][46] On his casting, Spall said, "Alien is one of the best films ever made, and it's a real buzz to be in a space suit on an Alien set with Ridley Scott coming and speaking to you. It's incredible. That's why I wanted to be an actor, to be in a space suit on an Alien set."[47]
Other cast members include Kate Dickie as the ship's medic, Ford;[46] Emun Elliott and Benedict Wong as, respectively, ship pilots Chance and Ravel;[48][49] and Patrick Wilson as Shaw's father.[50] Ian Whyte and Daniel James portray Engineers.[51]
