Y2K (also known as Countdown to Chaos and Y2K: The Movie) is a 1999 American made-for-television science fiction-thriller film directed by Dick Lowry and starring Ken Olin and Kate Vernon. The film takes a fictional look at the societal problems that could ensue from widespread computer shutdowns caused by the Year 2000 problem, also known as the Y2K problem or the Millennium bug. The film premiered November 21, 1999 on NBC.

The film's airing sparked a controversy after some utility and banking industry trade associations, including the Edison Electric Institute, asked TV stations not to air the film. Before the film aired, executive producer David Israel called the concerns "silly". "My guess is some of the things we say are going to happen might happen, and some we say might won't," he told Variety in November 1999. "It's not like Y2K is a big secret." The film was preceded by a disclaimer stating: "This program does not suggest or imply that any of these events could actually occur."

It was harshly criticized by critics as well as the technology press.