Turn Blue is the eighth studio album by American rock duo the Black Keys. It was released through Nonesuch Records on May 12, 2014, and co-produced by Danger Mouse and the duo. The record was their fourth collaboration with Danger Mouse, following their previous studio album, El Camino (2011), which was their biggest commercial and critical success to that point. For Turn Blue, Danger Mouse reprised his role from El Camino as an equal songwriting partner alongside guitarist Dan Auerbach and drummer Patrick Carney.

The Black Keys recorded the majority of Turn Blue at Sunset Sound in Hollywood, California, from July to August 2013, with additional recording taking place at Key Club in Benton Harbor, Michigan, and Auerbach's Easy Eye Sound Studio in Nashville, Tennessee, in early 2014. The sessions coincided with Auerbach's divorce from his wife, which inspired much of the album's lyrics. The resulting material was more melancholy and slower paced than the uptempo, hook-laden songs from El Camino. The album exhibits influences from psychedelic rock and soul, while also including the band's usual blues and garage rock sound. In addition to representing the record's moody tone, the title was selected as a homage to the "turn blue" catchphrase used by 1960s horror host Ghoulardi.

The band announced the album in March 2014 via a tweet by retired boxer Mike Tyson and a series of cryptic YouTube videos featuring a hypnotist. The song "Fever" was released as the lead single in March, and it charted in several countries. Four additional singles were released, including "Gotta Get Away", which was a rock radio success in North America. Turn Blue received favorable reviews from critics, many of whom commented on Danger Mouse's growing influence on the band. The album debuted at number one in the United States, Australia, and Canada, becoming the group's first record to top the charts in those countries. In May 2014, they embarked on a world tour in support of the album. At the 57th Annual Grammy Awards, Turn Blue was nominated for Best Rock Album, while "Fever" received nominations for Best Rock Performance and Best Rock Song.