"Deadalive" is the fifteenth episode of the eighth season of the science fiction television series The X-Files. It was written by executive producers Chris Carter and Frank Spotnitz, and was directed by Tony Wharmby. It explores the series' alien mythology story arc. Following its North American premiere on April 1, 2001, it received a Nielsen household rating of 7.3 and was watched by 12.4 million viewers. It garnered mixed reviews; while most critics were happy with the return of actor David Duchovny, some criticized the episode's plot holes. It later won the show's last Emmy Award, for Outstanding Makeup.

The eighth season of the American science fiction television series The X-Files commenced airing in the United States on November 5, 2000, concluded on May 20, 2001, and consisted of twenty-one episodes. Season eight takes place after Fox Mulder's alien abduction in the seventh season. The story arc for the search of Mulder continues until the second half of the season, while a new arc about Dana Scully's pregnancy is formed. This arc would continue, and end, with the next season. The season explores various themes such as life, death, and belief.