Horton Hears a Who! (film)

Horton Hears a Who! (also known as Dr. Seuss' Horton Hears a Who!) is a 2008 American computer animated adventure comedy film based on the book of the same name by Dr. Seuss, produced by Blue Sky Studios and distributed by 20th Century Fox. Directed by Jimmy Hayward and Steve Martino in their directorial debuts, the film's screenplay was written by Cinco Paul and Ken Daurio, and features the voices of Jim Carrey and Steve Carell as Horton the Elephant and Mayor Ned McDodd, respectively, alongside Carol Burnett, Will Arnett, Seth Rogen, Isla Fisher, and Amy Poehler. John Powell composed the film's music.

The film was released theatrically on March 14, 2008, and grossed $297 million on a budget of $85 million. Horton Hears a Who! was the third Dr. Seuss feature film adaptation, the first adaptation to be fully animated, and the second Dr. Seuss film starring Jim Carrey after How the Grinch Stole Christmas (2000).