The Flintstones in Viva Rock Vegas (also known as The Flintstones 2 or The Flintstones 2: Viva Rock Vegas in a working title) is a 2000 American romantic comedy film directed by Brian Levant, written by Jim Cash, Harry Elfont, Deborah Kaplan, and Jack Epps, Jr., and is the prequel to Levant's The Flintstones (1994), based on the 1960–1966 animated television series of the same name. It is set before the events of both the series and the first film, showing how Fred and Barney meet Wilma and Betty. The title is a play on the Elvis Presley song, Viva Las Vegas, also used as the title of an MGM musical film.

None of the original cast from the first film reprise their roles in this film. The film stars Mark Addy as Fred Flintstone, Stephen Baldwin as Barney Rubble, Kristen Johnston as Wilma Slaghoople, and Jane Krakowski as Betty O'Shale, replacing John Goodman, Rick Moranis, Elizabeth Perkins, and Rosie O'Donnell respectively. The supporting cast features Joan Collins, Thomas Gibson, Harvey Korman (in his final film performance), and Alan Cumming as both The Great Gazoo and Mick Jagged, a parody of Mick Jagger. William Hanna and Joseph Barbera, who created the original cartoon series, make cameo appearances at the end of the film.

The film was a box office bomb, grossing only $59.5 million against its $83 million budget. it also received mixed-to-negative reviews, though some critics considered it an improvement over the first film.