"Paranoid Android" is a song by Radiohead, from their third album, OK Computer. Despite its length of over six minutes, making it the longest released Radiohead song (including b-sides, excluding both remixes and the whole track 10 of the band's 2000 album Kid A), it was the first single from that album in 1997. The song's release marked the start of Radiohead's reputation as art rock innovators, and the album subsequently received huge acclaim.

Rolling Stone notes that the song "was recorded in actress Jane Seymour's fifteenth-century mansion, a house that Yorke was convinced was haunted". Bassist Colin Greenwood said "On 'Paranoid Android' what we were into was the idea of a DJ Shadow meets The Beatles thing." Thom Yorke also compared the song to The Beatles' work, saying "it really started out as three separate songs and we didn't know what to do with them. Then we thought of 'Happiness Is a Warm Gun' — which was obviously three different bits that John Lennon put together — and said 'Why don't we try that?'" Another influence, if not a direct homage, is 60's British band The Pretty Things, whose refrain in In The Square is replicated almost note-for-note during the chorus.

The structure of "Paranoid Android," though unique among Radiohead material, was also responsible for most of the comparisons with 1970s progressive rock that the band subsequently earned, much to their annoyance. Thom often refers to it as a "joke" song, though not derisively; the band continues to play it live at nearly every concert, usually toward the end of the set. It appeared at #256 on a Rolling Stone list of "500 Greatest Songs of All Time," slightly higher than "Fake Plastic Trees," another Radiohead entry which ranked #376. In August 2006 Q Magazine readers voted it the 10th greatest song of all-time. Its solo was ranked 34th by Guitar World readers in the list of the "100 Greatest Guitar Solos"

The song remains popular among fans of the band. In public polls to determine the favorite Radiohead song, "Paranoid Android" has won the top position several times, beating second place contenders such as "Idioteque," "Street Spirit" and "Pyramid Song" by landslides. In listings of the most downloaded and most played Radiohead songs on Internet-based services, "Paranoid Android" typically follows just behind "Creep", though unlike that song it receives virtually no mainstream radio exposure.