Jim Carrey als Horton (voice) | |
Steve Carell als Mayor (voice) | |
Carol Burnett als Kangaroo (voice) | |
Will Arnett als Vlad (voice) | |
Seth Rogen als Morton (voice) | |
Dan Fogler als Councilman / Yummo Wickersham (voice) | |
Isla Fisher als Dr. Mary Lou Larue (voice) | |
Jonah Hill als Tommy (voice) | |
Amy Poehler als Sally O'Malley (voice) | |
Jaime Pressly als Mrs. Quilligan (voice) | |
Charles Osgood als Narrator (voice) | |
Josh Flitter als Rudy (voice) | |
Niecy Nash-Betts als Miss Yelp (voice) | |
Jesse McCartney als JoJo (voice) | |
Shelby Adamowsky als Hedy / Hooly (voice) | |
Jack Angel als Old Time Who (voice) | |
Caitlin Rose Anderson als Helen (voice) | |
Emily Anderson als Heather (voice) | |
Jan Rabson als Town Cryer (voice) | |
John Cygan als Who (voice) | |
Jess Harnell als Another Who (voice) | |
Debi Derryberry als Who Mom (voice) | |
Samantha Droke als Hildy / Holly (voice) | |
Karen Disher als Who Kid (voice) | |
Marshall Efron als Wickersham Guard 1 (voice) | |
Bill Farmer als Willie Bear (voice) | |
Jason Fricchione als Joe (voice) | |
Heather Goldenhersh als Who Girl (voice) | |
Selena Gomez als Helga (voice) | |
Jimmy Hayward als Obnoxious Who (voice) | |
Joey King als Katie (voice) | |
Christina Martino als Heidi / Haley (voice) | |
Ellie Martino als Hanna (voice) | |
Laraine Newman als Glummox Mom (voice) | |
Tim Nordquist als Wickersham Guard 2 (voice) | |
Colleen O'Shaughnessey als Angela (voice) | |
Laura Ortiz als Jessica (voice) | |
Joe Pasquale als The Dentist (voice) | |
Connor Anderson als Who Child #1 (voice) | |
Isabella Acres als Additional Voices (voice) | |
Bob Bergen als Additional Voices (voice) | |
Jeff Biancalana als Additional Voices (voice) | |
Madison Davenport als Additional Voices (voice) | |
Teresa Ganzel als Additional Voices (voice) | |
Kathy Graves Toon als Additional Voice (voice) | |
Sherry Lynn als Additional Voices (voice) | |
Danny Mann als Additional Voices (voice) | |
Mona Marshall als Additional Voices (voice) | |
Mickie McGowan als Additional Voices (voice) | |
Madison Pettis als Additional Voices (voice) | |
Grace Rolek als Additional Voices (voice) | |
Jennessa Rose als Additional Voices (voice) | |
Ariel Winter als Additional Voices (voice) | |
Fletcher Sheridan als Jojo (singing voice) (uncredited) |
Steve Martino | Director |
Jimmy Hayward | Director |
John Powell | Original Music Composer |
Tim Nordquist | Editor |
Audrey Geisel | Executive Producer |
Cinco Paul | Screenplay |
Chris Wedge | Executive Producer |
Chris Meledandri | Executive Producer |
Bob Gordon | Producer |
Ken Daurio | Screenplay |
Bruce Anderson | Producer |
Jeannine Berger | Post Production Supervisor |
Arun Ram-Mohan | Lighting Artist |
Barry E. Jackson | Visual Development |
Moroni Taylor | Storyboard Artist |
Thomas Cardone | Art Direction |
Randy Thom | Sound Designer |
Nash Dunnigan | Set Designer |
Michael Knapp | Set Designer |
Kyle Macnaughton | Set Designer |
Jake Parker | Set Designer |
Guillermo Willie Real | Set Designer |
Lizette Vega | Set Designer |
Rhett Collier | Senior Visual Effects Supervisor |
Jamie Kirschenbaum | Senior Visual Effects Supervisor |
Alen Lai | Senior Visual Effects Supervisor |
Randy Thom | Supervising Sound Editor |
Dennis Leonard | Supervising Sound Editor |
Thomas A. Carlson | Supervising Music Editor |
Paul Downs | Animation |
Dr. Seuss | Book |
J.G. Quintel | Additional Storyboarding |
Ricardo Curtis | Head of Story |
Christian Kaplan | Casting |
David Esneault | Lighting Director |
Jeff Biancalana | Storyboard Artist |
Cal Brunker | Storyboard Artist |
Jony Chandra | Storyboard Artist |
Karen Disher | Storyboard Artist |
Eric Favela | Storyboard Artist |
William H. Frake III | Storyboard Artist |
Martin Fuller | Storyboard Artist |
Tony Maki | Storyboard Artist |
Chris Renaud | Storyboard Artist |
Rafael Zentil | Storyboard Artist |
Stephanie Arnett | Additional Storyboarding |
Crystal Chesney | Additional Storyboarding |
Jeff Siergey | Additional Storyboarding |
Edmund Fong | Additional Storyboarding |
Chris Gilligan | Additional Storyboarding |
Frank Marino | Additional Storyboarding |
Rich Moore | Additional Storyboarding |
Wilbert Plijnaar | Additional Storyboarding |