The Thing is a 1982 American science fiction horror film directed by John Carpenter from a screenplay by Bill Lancaster. Based on the 1938 John W. Campbell Jr. novella Who Goes There?, it tells the story of a group of American researchers in Antarctica who encounter the eponymous "Thing", an extraterrestrial life-form that assimilates, then imitates, other organisms. The group is overcome by paranoia and conflict as they learn that they can no longer trust each other and that any of them could be the Thing. The film stars Kurt Russell as the team's helicopter pilot R.J. MacReady, with A. Wilford Brimley, T. K. Carter, David Clennon, Keith David, Richard Dysart, Charles Hallahan, Peter Maloney, Richard Masur, Donald Moffat, Joel Polis, and Thomas G. Waites in supporting roles.

Production began in the mid-1970s as a faithful adaptation of the novella, following 1951's The Thing from Another World. The Thing went through several directors and writers, each with different ideas on how to approach the story. Filming lasted roughly twelve weeks, beginning in August 1981, and took place on refrigerated sets in Los Angeles as well as in Juneau, Alaska, and Stewart, British Columbia. Of the film's $15 million budget, $1.5 million was spent on Rob Bottin's creature effects, a mixture of chemicals, food products, rubber, and mechanical parts turned by his large team into an alien capable of taking on any form.

The Thing was released in 1982 to negative reviews that described it as "instant junk" and "a wretched excess". Critics both praised the special effects achievements and criticized their visual repulsiveness, while others found the characterization poorly realized. The film grossed $19.6 million during its theatrical run. Many reasons have been cited for its failure to impress audiences: competition from films such as E.T. the Extra-Terrestrial, which offered an optimistic take on alien visitation; a summer that had been filled with successful science fiction and fantasy films; and an audience living through a recession, diametrically opposed to The Thing's nihilistic and bleak tone.

The film found an audience when released on home video and television. In the subsequent years, it has been reappraised as one of the best science fiction and horror films ever made and has gained a cult following. Filmmakers have noted its influence on their work, and it has been referred to in other media such as television and video games. The Thing has spawned a variety of merchandise – including a 1982 novelization, "haunted house" attractions, board games – and sequels in comic books, a video game of the same title, and a 2011 prequel film of the same title.