Here you'll find pictures from the 20th Century Fox produced movie Horton Hears a Who!. Pictured below are director Jimmy Hayward, Steve Martino and stars VOICES: Jim Carrey (Horton), Steve Carell (Mayor of Whoville), Carol Burnett, Will Arnett, Seth Rogen, Dan Fogler, Isla Fisher, Jonah Hill, Amy Poehler, Jamie Pressly.