Favourite Worst Nightmare is the second studio album by English rock band Arctic Monkeys, first released in Japan on 18 April 2007 and released in their home country of United Kingdom on 23 April 2007 by Domino Recording Company. Recorded in East London's Miloco Studios with producers James Ford and Mike Crossey, the album was preceded by the release of lead single "Brianstorm" on 2 April 2007. It was the band’s first album with new bassist Nick O'Malley, replacing their previous bassist Andy Nicholson, who left the band shortly before the North American tour of the band's debut studio album, Whatever People Say I Am, That’s What I’m Not (2006).

In comparison to their debut album, the album is considered more musically ambitious, with ambient sounds and expanded drum rhythms being introduced. As with their debut, Favourite Worst Nightmare was a widespread critical success, with critics highlighting the band's new emotional depth and frontman Alex Turner's matured songwriting. NME and Uncut ranked it the second-best album of 2007, while Dutch publication OOR named it the best of 2007. Retrospectively, the album is considered the start of the band's change of sound with each of their albums after their debut.

In its first week of release, the album sold over 227,000 copies in the United Kingdom, going straight to number one on the UK Albums Chart. "Brianstorm" and "Fluorescent Adolescent" were also both hits on the UK Singles Chart, with the former reaching number two on the chart. In the United States, the album debuted at number seven on the Billboard 200, selling approximately 44,000 copies in its first week. The album has since been certified 4× platinum in the UK. It was nominated for the 2007 Mercury Prize and won Best British Album at the 2008 Brit Awards.