"Colossal" held its world premiere at the Toronto International Film Festival on 9 September 2016 and was followed by several festival screenings. It was theatrically released in the United States on April 7, 2017 by Neon, in South Korea on April 20 by Dreamfact Entertainment, in Canada on April 21 by Mongrel Media, and in Spain on June 30 by Versus Entertainment; it aired a day earlier, on June 29, on as an exclusive preview. The film received positive reviews, with praise for the acting, direction, screenplay, and themes. Hathaway was singled out by many critics for particular acclaim. The film grossed $4.5 million worldwide against a production budget of $15 million.