
| Directed by Jimmy Hayward Steve Martino Screenplay Ken Daurio Cinco Paul Dr. Seuss Jeff Siergey Produced by Audrey Geisel Bob Gordon Christopher Meledandri Chris Wedge Original Music by John Powell | Cast Jim Carrey Horton Steve Carell The Mayor of Who-ville (voice) Carol Burnett Kangaroo (voice) Dane Cook (voice) Will Arnett (voice) Seth Rogen (voice) Dan Fogler Yummo (voice) Isla Fisher (voice) Jonah Hill (voice) Amy Poehler (voice) Adewale Akinnuoye-Agbaje Town Crier (voice) Jaime Pressly (voice) Josh Flitter Rudy (voice) Niecy Nash Miss Yelp Jesse McCartney JoJo Shelby Adamowsky The Mayor's Daughter Jack Angel Old Time Who / Additional Voices Jan Rabson Town Cryer / Additional Voices John Cygan Who / Additional Voices Jess Harnell Another Who / Additional Voices Debi Derryberry Who Mom Samantha Droke Mayor's Daughter (voice) Karen Disher Who Kid Marshall Efron Wickersham Guard #1 Bill Farmer Willie Bear / Additional Voices Jason Fricchione Joe Heather Goldenhersh Who Girl / Additional Voices Selena Gomez Helga Jimmy Hayward Obnoxious Who Joey King Katie Laraine Newman Glummox Mom / Additional Voices Colleen O'Shaughnessey Angela / Additional Voices Laura Ortiz Jessica Joe Pasquale The Dentist Mona Marshall Additional Voices Mickie McGowan Additional Voices Bob Bergen Additional Voices Madison Pettis Additional Voices Madison Davenport Additional Voices Teresa Ganzel Additional Voices Ariel Winter Additional Voices Danny Mann Additional Voices |