Music critic Robert Christgau considers "Slip Kid" one of the two songs on "The Who by Numbers" to "break out of the bind" of joylessness he finds on the album. Author John Atkins considers it "a perfect performance that bridges a classical Who song structure with Townshend's revisionist lyrics and hints at a darker mood that becomes more evident as the album progresses." AllMusic critic Stephen Thomas Erlewine praises the song's "simple power." "Rolling Stone" named the song the 36th best Who song, while "Ultimate Classic Rock" ranked the song the 12th best Who song ever, saying, "Easily the most underrated single in the Who's career, 'Slip Kid' is special". "Ultimate Classic Rock" also ranked the song the most underrated Who song.