"The Iron Giant" received positive reviews from critics. On Rotten Tomatoes, the film holds a 96% approval rating based on 143 reviews, with an average rating of 8.21/10. The website's critics consensus reads, "The endearing "Iron Giant" tackles ambitious topics and complex human relationships with a steady hand and beautifully animated direction from Brad Bird." Metacritic, which uses a weighted average, assigned the film a score of 85 out of 100 based on 29 critics, indicating "universal acclaim". Audiences polled by CinemaScore gave the film an average grade of "A" on an A+ to F scale. The Reel Source forecasting service calculated that "96–97%" of audiences that attended recommended the film.