Gavin & Stacey is a British sitcom written by James Corden and Ruth Jones about two families: one in Billericay, Essex; one in Barry, Vale of Glamorgan. Mathew Horne and Joanna Page play the eponymous characters Gavin and Stacey, while Corden and Jones star as Smithy and Nessa. Alison Steadman and Larry Lamb star as Gavin's parents (Pam and Mick), and Melanie Walters (Gwen) is Stacey's mother and Rob Brydon (Bryn) is Stacey's uncle.

Baby Cow Productions produced the sitcom for BBC Wales. Three series totalling twenty episodes were broadcast from 13 May 2007 to 1 January 2010 on BBC Three and later on BBC One. Broadcast on Christmas Day 2009 and New Year's Day 2010, episodes of the final series formed a significant part of the prime-time BBC seasonal programming.

Gavin & Stacey was directed by Christine Gernon who had previously directed other BBC sitcoms such as One Foot in the Grave. Acclaimed as both a hit and a breakthrough show for the BBC, it was the most nominated show in the 2007 British Comedy Awards. It won several awards, including the British Academy Television Awards (BAFTAs) Audience Award, and the British Comedy Awards Best TV Comedy Award, both in 2008. In 2019, Gavin & Stacey was named the 17th-greatest British sitcom in a poll by Radio Times.Corden and Jones wrote a Christmas Day 2019 special for BBC One. With 18.49 million viewers, the broadcast in the United Kingdom was the most-viewed non-sporting event in a decade and the most-watched comedy in 17 years.