The song received polarised reviews from music critics. In his review of the album for the New Yorker, Nick Hornby mentioned the song as "an unpleasant free-jazz workout, with a discordant horn section squalling over a studiedly crude bass line". Mark Beaumont, who disparaged Kid A in Melody Maker on its release, wrote ten years later that the "free-form jazz horns" of "The National Anthem" produced a "mingus-in-a-tumble-dryer racket". Lorraine Ali, writing for Newsweek, described the song as "annoying pileup of squawking instruments". Rob Sheffield of Rolling Stone said the horn section "was a cornier-than-usual art-rock cliché, trying way too hard for a way-too-obvious gimmick".
