First seen in 1979 in the Dan O'Bannon/Ridley Scott masterpiece Alien, the acid-blooded, cold-hearted Alien has become easily one of Hollywood's most iconic science-fiction monsters, and has since broken out into popular culture with hundreds of references from various sources. While the sequels—particularly in the 1990s, with Alien³ and Alien: Resurrection—were arguably not up to par with Ridley Scott's Alien and its sequel, James Cameron's Aliens, the series remains ones of the best-known and recognizable sci-fi franchises ever.

Alien was nominated for two Academy Awards, winning for Best Visual Effects. Aliens received seven nominations, including a Best Actress nomination for Sigourney Weaver, and won for Best Visual Effects and Best Sound Effects. Alien 3 was nominated for Best Visual Effects. Alien was also inducted into the National Film Registry of the Library of Congress for historical preservation as a film which is "culturally, historically, or aesthetically significant". The American Film Institute ranked Alien as the sixth most thrilling American movie and seventh-best film in the science fiction genre, and in the AFI's 100 Years... 100 Heroes and Villains list, Ripley was ranked eighth among the heroes, and the Alien was fourteenth among the villains.