 Robert Copsey of Digital Spy called it "anthemic" and noted the song would become a future single. Rich Juzwiak of The Village Voice called "I Wanna Go" the highlight of the album, and said "get ready for [it] to score your summer." However, Juzwiak went on to note that Spears'vocals are heavily manipulated to maximize the chorus's potential, even though "the joy she sings about is palpable." The Chicago Sun-Times journalist Thomas Conner also noted that the singer's vocals were processed to the point "these songs could be sung by anyone", exemplifying "' I Wanna Go 'tweaks her up so high she could be Jackie Evancho." Andy Gill of The Independent also criticized the singer's vocals on Femme Fatale, stating that they sounded more programmed than natural, with "even the little whistling hook in 'I Wanna Go' has a synthetic character about it."
