"It was the most incredible preview I've ever been in. I mean, people were screaming and running out of the theater."—Editor Terry Rawlings describing the film's screening in Dallas.
An initial screening of Alien for 20th Century Fox representatives in St. Louis suffered from poor sound in the theater. A subsequent screening in a newer theater in Dallas went significantly better, eliciting genuine fright from the audience. Two theatrical trailers were shown to the public. The first consisted of rapidly changing still images set to some of Jerry Goldsmith's electronic music from Logan's Run. The second used test footage of a hen's egg set to part of Goldsmith's Alien score. The film was previewed in various American cities in the spring of 1979 and was promoted by the tagline "In space no one can hear you scream."
Alien was rated "R" in the United States, "X" in the United Kingdom, and "M" in Australia. In the UK, the British Board of Film Classification almost passed the film as an "AA" (for ages 14 and over), although there were concerns over the prevalent sexual imagery. 20th Century Fox eventually relented in pushing for an AA certificate after deciding that an X rating would be a better choice commercially for selling a horror film.
Alien opened in American theaters on May 25, 1979. The film had no formal premiere, yet moviegoers lined up for blocks to see it at Grauman's Egyptian Theatre in Hollywood where a number of models, sets, and props were displayed outside to promote it during its first run. Religious zealots set fire to the model of the space jockey, believing it to be the work of the devil. In the United Kingdom, Alien premiered at a gala performance at the Edinburgh Film Festival on September 1, 1979, before starting an exclusive run at the Odeon Leicester Square in London on September 6, 1979, but it did not open widely in Britain until January 13, 1980.
Critical reaction to the film was initially mixed. Some critics who were not usually favorable towards science fiction, such as Barry Norman of the BBC's Film series, were positive about the film's merits. Others, however, were not: Reviews by Variety, Sight and Sound, Vincent Canby and Leonard Maltin were mixed or negative. (Maltin, however, reassessed the film upon the release of the Director's Cut and gave Alien a positive review.) A review by Time Out said the film was an "empty bag of tricks whose production values and expensive trickery cannot disguise imaginative poverty". In a 1980 episode of Sneak Previews discussing science fiction films of the 1950s and 1970s, critics Gene Siskel and Roger Ebert were critical of Alien. Ebert called it "basically just an intergalactic haunted house thriller set inside a spaceship" and one of several science fiction pictures that were "real disappointments" compared to Star Wars, Close Encounters of the Third Kind, and 2001: A Space Odyssey, though he did compliment the early scene of the Nostromo's crew exploring the alien planet as showing "real imagination". However, the film later made it onto Ebert's Great Movies list, giving it four stars and stating, "Ridley Scott's 1979 movie is a great original."
The film was a commercial success, making $78,900,000 in the United States and £7,886,000 in the United Kingdom during its first run. It ultimately grossed $80,931,801 in the United States, though international box office figures have varied from $24,000,000 to $122,700,000. Its total worldwide gross has been listed within the range of $104,931,801 to $203,630,630.
According to 20th Century Fox accounts, however, by April 1980 when the film had earned a reported $100 million at the box office, after advertising, distribution fees, penalties and other costs were deducted, it was still recorded as having made a loss to the studio of $2.4 million. This was seen as an example of Hollywood creative accounting and was much criticised. By August 1980 Fox was saying the film was $4 million in profit.
Alien won the 1979 Academy Award for Visual Effects and was also nominated for Best Art Direction (for Michael Seymour, Leslie Dilley, Roger Christian, and Ian Whittaker). It won Saturn Awards for Best Science Fiction Film, Best Direction for Ridley Scott, and Best Supporting Actress for Veronica Cartwright, and was also nominated in the categories of Best Actress for Sigourney Weaver, Best Make-up for Pat Hay, Best Special Effects for Brian Johnson and Nick Allder, and Best Writing for Dan O'Bannon. It was also nominated for British Academy of Film and Television Arts (BAFTA) awards for Best Costume Design for John Mollo, Best Editing for Terry Rawlings, Best Supporting Actor for John Hurt, and Most Promising Newcomer to Leading Film Role for Sigourney Weaver. It also won a Hugo Award for Best Dramatic Presentation and was nominated for a British Society of Cinematographers award for Best Cinematography for Derek Vanlint, as well as a Silver Seashell award for Best Cinematography and Special Effects at the San Sebastián International Film Festival. Jerry Goldsmith's score received nominations for the Golden Globe Award for Best Original Score, the Grammy Award for Best Soundtrack Album, and a BAFTA Award for Best Film Music.
Alien has been released in many home video formats and packages over the years. The first of these was a seventeen-minute Super-8 version for home projectionists. It was also released on both VHS and Betamax for rental, which grossed it an additional $40,300,000 in the United States alone. Several VHS releases were subsequently sold both singly and as boxed sets. LaserDisc and Videodisc versions followed, including deleted scenes and director commentary as bonus features. A VHS box set containing Alien and the sequels Aliens and Alien 3 was released in facehugger-shaped boxes, including some of the deleted scenes from the Laserdisc editions. When Alien Resurrection premiered in theaters, another set of the first three films was released including a Making of Alien Resurrection tape. A few months later the set was re-released with the full version of Alien Resurrection taking the place of the making-of video. Alien was released on DVD in 1999, both singly and packaged with Aliens, Alien 3 and Alien Resurrection as The Alien Legacy. This set, which was also released in a VHS version, included a commentary track by Ridley Scott. The first three films of the series have also been packaged as the Alien Triple Pack.
"The traditional definition of the term 'Director's Cut' suggests the restoration of a director's original vision, free of any creative limitations. It suggests that the filmmaker has finally overcome the interference of heavy-handed studio executives, and that the film has been restored to its original, untampered form. Such is not the case with Alien: The Director's Cut. It's a completely different beast."—Ridley Scott
In 2003 20th Century Fox was preparing the Alien Quadrilogy DVD box set, which would include Alien and its three sequels. In addition, the set would also include alternate versions of all four films in the form of "special editions" and "director's cuts". Fox approached Ridley Scott to digitally restore and remaster Alien, and to restore several scenes which had been cut during the editing process for inclusion in an expanded version of the film. Upon viewing the expanded version, Scott felt that it was too long and chose to recut it into a more streamlined alternate version:
Upon viewing the proposed expanded version of the film, I felt that the cut was simply too long and the pacing completely thrown off. After all, I cut those scenes out for a reason back in 1979. However, in the interest of giving the fans a new experience with Alien, I figured there had to be an appropriate middle ground. I chose to go in and recut that proposed long version into a more streamlined and polished alternate version of the film. For marketing purposes, this version is being called "The Director's Cut."
The "Director's Cut" restored roughly four minutes of deleted footage while cutting about five minutes of other material, leaving it about a minute shorter than the theatrical cut. Many of the changes were minor, such as altered sound effects, while the restored footage included the scene in which Ripley discovers the cocooned Dallas and Brett during her escape of the Nostromo. Fox decided to release the Director's Cut in theaters, and it premiered on October 31, 2003. The Alien Quadrilogy box set was released December 2, 2003, with both versions of the film included along with a new commentary track featuring many of the film's actors, writers, and production staff, as well as other special features and a documentary entitled The Beast Within: The Making of Alien. Each film was also released separately as a DVD with both versions of the film included. Scott noted that he was very pleased with the original theatrical cut of Alien, saying that "For all intents and purposes, I felt that the original cut of Alien was perfect. I still feel that way", and that the original 1979 theatrical version "remains my version of choice". He has since stated that he considers both versions "director's cuts", as he feels that the 1979 version was the best he could possibly have made it at the time.
The Alien Quadrilogy set earned Alien a number of new awards and nominations. It won DVDX Exclusive Awards for Best Audio Commentary and Best Overall DVD, Classic Movie, and was also nominated for Best Behind-the-Scenes Program and Best Menu Design. It also won a Sierra Award for Best DVD, and was nominated for a Saturn Award for Best DVD Collection and Golden Satellite Awards for Best DVD Extras and Best Overall DVD. In 2010 both the theatrical version and Director's Cut of Alien were released on Blu-ray Disc, as a stand-alone release and as part of the Alien Anthology set.
In 2014, to mark the 35th anniversary of the release of the film, a special rerelease box set named Alien: 35th Anniversary Edition, containing the film on Blu-ray, a Digital HD copy, a reprint of Alien: The Illustrated Story, and a series of collectible art cards containing artwork by H.R. Giger related to the film, was released. The disk itself is the same as the respective disk on the 2010 Anthology Blu-ray release, and contains MU-TH-UR mode, despite the lack of the required bonus disk. A reprint of the novel by Alan Dean Foster was also released.