"Under a Blood Red Sky" is a live mini-album by Irish rock band U2, produced by Jimmy Iovine and released on 21 November 1983. The album features eight tracks, which were compiled from three different concerts during the band's 1983 War Tour. Two of these tracks were recorded at the band's iconic 5 June performance at Red Rocks Amphitheatre in Colorado. The accompanying concert film, U2 Live at Red Rocks: Under a Blood Red Sky, was recorded at the same show and released as a companion to the album. Both the album and film helped to solidify U2's reputation as a world-class live act.
The album features live recordings from shows in the US (Colorado and Boston) and in Germany. The tracklist includes two songs from the Red Rocks performance, which became a defining moment in the band's early career.
The title Under a Blood Red Sky is derived from the lyrics of "New Year's Day," a track from U2's War album.
The album was remastered and re-released on 29 September 2008, as a CD with a DVD of the Red Rocks concert. In November 2023, U2 marked the 40th anniversary of the album with a newly remastered edition released on Record Store Day Black Friday.