After the stress of promoting Radiohead's acclaimed 1997 album OK Computer, songwriter Thom Yorke envisioned a radical change in direction. The band incorporated synthesisers, drum machines, strings and brass, drawing influence from electronic music, ambient, krautrock, jazz, and 20th-century classical music. They recorded Kid A with OK Computer producer Nigel Godrich in Paris, Copenhagen, Gloucestershire and their hometown Oxford, England. Another album recorded in the same sessions, Amnesiac, was released the following year.

Radiohead released no singles or music videos to promote Kid A and conducted few interviews and photoshoots. Instead, they became one of the first major acts to use the internet as a promotional tool; the album was made available to stream and was promoted with short animated films featuring music and artwork. Bootlegs of early performances were shared on file-sharing services, and the album was leaked before release.

Kid A debuted at the top of the charts in Britain, where it went platinum in the first week. It also became Radiohead's first number-one album in the United States. Like OK Computer, it won a Grammy for Best Alternative Album and was nominated for Album of the Year. Its departure from Radiohead's earlier sound divided fans and critics, and some dismissed it as pretentious, deliberately obscure, or derivative. However, Kid A later attracted wider acclaim; at the turn of the decade, Rolling Stone, Pitchfork and the Times ranked Kid A the greatest album of the 2000s. In 2012, Rolling Stone ranked it number 67 on its list of the 500 greatest albums of all time.