Humbug is the third studio album by English rock band Arctic Monkeys, first released on 19 August 2009 through Domino Recording Company. The band started to write new material for the album towards the end of summer 2008 and finished it entirely in spring 2009. Like their previous release, Favourite Worst Nightmare (2007), Humbug was released first in Japan, followed by Australia, Brazil, Ireland, and Germany, on 21 August 2009. It was then released in the UK on 24 August 2009, in the US the following day, and in Greece on 31 August.

Wholly recorded in the United States, the band worked with American musician Josh Homme, who produced tracks recorded in Los Angeles and the Mojave Desert alongside New York City recordings produced by James Ford. Musically, the album is a departure from the garage rock and punk-influenced sound of the band's previous work, incorporating elements of stoner rock, desert rock, surf rock, and ambient tones. Homme has been credited by writers for introducing the album's darker sound. Percussion instruments were used on the album, including xylophones, glockenspiels, and shakers. Frontman Alex Turner's vocals on the album are noted as a drastic change from the frenetic and upbeat delivery of Arctic Monkeys' previous albums to a slower and more hushed approach. Turner's songwriting also is a departure from his kitchen-sink realism poetry, instead being replaced by analogy.

The album's release preceded the band's headlining performances at the Reading and Leeds Festivals at the end of that week. It topped the UK Albums Chart and has been certified platinum in the UK. Though Humbug did not receive the extent of acclaim that both Whatever People Say I Am, That's What I'm Not (2006) and Favourite Worst Nightmare did by critics, it nevertheless received generally positive reviews, with critics noting that the band expanded their sound and themes, while the album's tone was recognised as darker than the band's previous records. Retrospectively, Humbug is considered one of the band's most important records, with many noting it as containing various musical styles and lyrical themes the band would further explore on later releases.