Cast of Horton Hears a Who!

Jim Carrey lends his voice to Horton, a compassionate and kind-hearted elephant who hears a tiny speck of dust talking to him.

Steve Carell voices the character of the Mayor, who is the leader of Whoville and is determined to save his tiny town from danger.

Carol Burnett provides the voice for Kangaroo, a skeptical and uptight character who questions Horton's beliefs.

Will Arnett voices Vlad, a vulture with a mischievous streak who causes trouble for Horton and the Whos.

Seth Rogen plays Morton, a well-meaning but clumsy mouse who befriends Horton in his mission to protect the Whos.

Dan Fogler voices Councilman and Yummo Wickersham, characters who add humor and charm to the story.

Isla Fisher portrays Dr. Mary Lou Larue, a distinguished scientist in Whoville who assists the Mayor in saving their town.

Jonah Hill voices Tommy, a young Who who gets caught up in the chaos unfolding in Whoville.

Amy Poehler lends her voice to Sally O'Malley, a spirited and supportive character in Whoville.

Jaime Pressly voices Mrs. Quilligan, a caring and protective mother figure in Whoville.

Charles Osgood serves as the Narrator, guiding viewers through the whimsical world of Whoville and Horton's adventures.

Josh Flitter voices Rudy, a young Who who looks up to Horton and helps in the efforts to save Whoville.