Whatever People Say I Am, That's What I'm Not is the debut studio album by English rock band Arctic Monkeys, released on 23 January 2006 in the United Kingdom by Domino Recording Company and on 21 February 2006 in the United States. The album includes their first two singles "I Bet You Look Good on the Dancefloor" and "When the Sun Goes Down", as well as re-recorded versions of both tracks from the band's debut EP, Five Minutes with Arctic Monkeys. This is the only Arctic Monkeys album to feature bassist Andy Nicholson, as he left the band shortly after the album's release.

Forming in 2002, Arctic Monkeys frequently gave away free demo CDs to fans at gigs, which resulted in fans uploading the band's music to social media sites. As their attention hugely grew, the band had garnered great demand from fans, the press and the music industry. Several of the album's tracks had been released for free via the Internet in late 2004, which consolidated on the unofficial Beneath the Boardwalk compilation. Musically, Whatever People Say I Am, That's What I'm Not features indie rock, garage rock revival, post-punk revival, punk rock, alternative rock, and post-Britpop. Its thematic content has been likened to a concept, generally concerning nightlife, including lyricism surrounding clubbing and pub culture, and romance from the perspective of young Northerners.

Prior to the release of Whatever People Say I Am, That's What I'm Not, Arctic Monkeys achieved their first UK number-ones with "I Bet You Look Good on the Dancefloor", which was the most acclaimed song of 2005, and "When the Sun Goes Down". The album became the fastest selling debut album in British music history, selling over 360,000 copies in its first week, and remains the fastest selling debut album by a band. It has since gone 7× platinum in the UK. In the US, it also became the second-fastest selling independent record label debut album in history and was certified gold by the RIAA for selling 500,000 copies there.

The album received widespread critical acclaim from critics for its depiction of youth British culture and for resurging British indie music that had waned after the 1990s. Among its accolades included being named the best album of 2006 by Time magazine, winning the Brit Award for Best British Album, winning the 2007 Mercury Prize, and receiving a Grammy Award nomination for Best Alternative Music Album. It has been ranked in several greatest albums lists, including 371 in Rolling Stone's “500 Greatest Albums of All Time”, 19 in NME's “500 Greatest Albums of All Time”, and 30 in Rolling Stone's 100 Best Debut Albums of All Time.