Production notes

In 1997, Sony Pictures Entertainment purchased the film rights to Astro Boy from Tezuka Productions, intending to produce a live-action feature film. Todd Alcott was set to write the screenplay, but the film halted in 2000 when Steven Spielberg began A.I. Artificial Intelligence (2001), another film with a robot boy who replaces a dead child. In December 2001, Sony hired Eric Leighton to direct an all-CGI film, with Angry Films and Jim Henson Productions producing it for a 2004 release. A screenplay draft was written, but the film did not go into production, and Leighton left in early 2003 to pursue other film projects. In June 2004, animator and Dexter's Laboratory creator Genndy Tartakovsky was hired to direct a live-action/animatronics/CGI feature film. A script was written, but the film did not go into production, and Tartakovsky left the next year to direct 3-D-animated feature films at a new studio, Orphanage Animation Studios. A few months later it was revealed that he was set to direct The Dark Crystal (1982) sequel, The Power of the Dark Crystal, another co-production with Jim Henson Productions. In September 2006, it was announced that Hong Kong-based animation firm Imagi Animation Studios would produce a CGI animated Astro Boy film, with Colin Brady directing. A year later, the studio made a three-picture distribution deal with Warner Bros. and The Weinstein Company, which also included TMNT (2007) and Gatchaman. In 2008, Summit Entertainment, Which is before Lionsgate Films acquired, Took over the distribution rights. The same year, Brady was replaced with David Bowers, who previously directed Flushed Away (2006), the last project under the relationship between DreamWorks Animation, the creators of the Shrek and Madagascar franchises, and Aardman Animations, the creators of the Wallace & Gromit franchise and Chicken Run.

Like TMNT, the film was CGI animated on Maya and rendered on Pixar's RenderMan at Imagi's Los Angeles facility and its main studio in Hong Kong. Some changes to Astro's design had to be made in order to appeal to a western audience and making the leap to CGI. The more challenging was his kawaii portrayal, part of which were his large eyes and curly eyelashes, features that the filmmakers thought made him too feminine. Imagi had several discussions on how round and curvy Astro's body proportions should be and in the end they were made slimmer. The by-product of these changes was Astro's Caucasian look. In early development Astro's design was young, resembling his iconic design of a 9-year-old boy. The design team changed that and made him look like a 13-year-old to appeal to a larger audience. They also gave him a white shirt and a blue jacket, replacing the character's traditional shirtless appearance, since they thought it would be strange to have a normal boy running around without a shirt. They also replaced his heart-shaped energy core with a glowing blue one.

The score to Astro Boy was composed by John Ottman, who recorded his score with a 95-piece orchestra and choir at Abbey Road Studios. A soundtrack album was released on October 20, 2009, by Varèse Sarabande Records. Songs in Astro Boy not composed by John Ottman are as follows: Breezy Day, composed by Roger-Roger. Alright, written by Daniel Goffey, Gaz Coombes, and Michael Quinn and performed by Supergrass. Marching Down the Field, composed by Harry Edwards.