Joey Nolfi from Entertainment Weekly called the song an "epic collaboration" and "a mouthwatering serve". Michael Roffman from Consequence of Sound said that "'Sour Candy' is another banger from the Oscar winner, proving Chromatica will bring the party to our pandemic." Claire Shaffer from Rolling Stone found it "a sugar-sweet club track for all our at-home parties. Jem Asward from Variety found it "a sparkling combination of the two artists' styles". Zoe Haylock from Vulture opined that "when the lyrics can basically all be Instagram captions, you know it's a good pop song!" Cole Delbyck of HuffPost thought that the song is "fusing Gaga and Blackpink's distinct sounds into one dance-floor-primed... bop" and "lives up to the hype surrounding the long in the works collaboration that fans have been filling up their mentions about for years".
Louise Bruton from The Irish Times found it "the perfect mix of weirded-out pop and euphoria". Stephen Daw from Billboard complimented the song for managing to give every participants "equal, well-balanced time", although he noted that something was missing from the track that "could have rounded [it] out". Michael Cragg from The Guardian was critical of the song, saying that it "falls disappointingly flat" and "ends up sounding like a dashed off, cheaply produced interlude". Sal Cinquemani from Slant Magazine called the song "empty-calorie", while Evan Sawdey from PopMatters thought it was "blissfully short" and one of the "lesser songs" of the Chromatica album.