Takk... is the fourth studio album by the Icelandic post-rock band Sigur Rós, first released in the United States by Geffen Records on 12 September 2005. The album debuted at number 27 on the US Billboard 200, selling 30,000 copies in its first week.

Sigur Rós is an Icelandic post-rock band that formed in 1994 in Reykjavík. It comprises lead vocalist and guitarist Jón Þór "Jónsi" Birgisson, bassist Georg Hólm and keyboardist Kjartan Sveinsson. Known for their ethereal sound, frontman Jónsi's falsetto vocals, and their use of bowed guitar, Sigur Rós incorporate classical and minimal aesthetic elements. Jónsi's vocals are sung in Icelandic and non-linguistic vocalisations the band terms Vonlenska. They have released eight studio albums, and attracted critical and commercial attention with their second album Ágætis byrjun.