Cast
Jim Carrey
Horton (voice)
Steve Carell
Mayor (voice)
Carol Burnett
Kangaroo (voice)
Will Arnett
Vlad (voice)
Seth Rogen
Morton (voice)
Dan Fogler
Councilman / Yummo Wickersham (voice)
Isla Fisher
Dr. Mary Lou Larue (voice)
Jonah Hill
Tommy (voice)
Amy Poehler
Sally O'Malley (voice)
Jaime Pressly
Mrs. Quilligan (voice)
Charles Osgood
Narrator (voice)
Josh Flitter
Rudy (voice)
Niecy Nash-Betts
Miss Yelp (voice)
Jesse McCartney
JoJo (voice)
Shelby Adamowsky
Hedy / Hooly (voice)
