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

Miss Yelp (voice)

Jesse McCartney

JoJo (voice)

Shelby Adamowsky

Hedy / Hooly (voice)

Jack Angel

Old Time Who (voice)

Caitlin Rose Anderson

Helen (voice)

Emily Anderson

Heather (voice)

Jan Rabson

Town Cryer (voice)

John Cygan

Who (voice)

Jess Harnell

Another Who (voice)

Debi Derryberry

Who Mom (voice)

Samantha Droke

Hildy / Holly (voice)

Karen Disher

Who Kid (voice)

Marshall Efron

Wickersham Guard 1 (voice)

Bill Farmer

Willie Bear (voice)

Jason Fricchione

Joe (voice)

Heather Goldenhersh

Who Girl (voice)

Selena Gomez

Helga (voice)

Jimmy Hayward

Obnoxious Who (voice)

Joey King

Katie (voice)

Christina Martino

Heidi / Haley (voice)

Ellie Martino

Hanna (voice)

Laraine Newman

Glummox Mom (voice)

Tim Nordquist

Wickersham Guard 2 (voice)

Colleen O'Shaughnessey

Angela (voice)

Laura Ortiz

Jessica (voice)

Joe Pasquale

The Dentist (voice)

Connor Anderson

Who Child #1 (voice)

Isabella Acres

Additional Voices (voice)

Bob Bergen

Additional Voices (voice)

Jeff Biancalana

Additional Voices (voice)

Madison Davenport

Additional Voices (voice)

Teresa Ganzel

Additional Voices (voice)

Kathy Graves Toon

Additional Voice (voice)

Sherry Lynn

Additional Voices (voice)

Danny Mann

Additional Voices (voice)

Mona Marshall

Additional Voices (voice)

Mickie McGowan

Additional Voices (voice)

Madison Pettis

Additional Voices (voice)

Grace Rolek

Additional Voices (voice)

Jennessa Rose

Additional Voices (voice)

Ariel Winter

Additional Voices (voice)

Fletcher Sheridan

Jojo (singing voice) (uncredited)

Steve Martino

Director

Jimmy Hayward

Director

Ken Daurio

Guión, Guión Adaptado

Cinco Paul

Guión, Guión Adaptado

Dr. Seuss

Guión, Libro

Ricardo Curtis

Head of Story

John Powell

Compositor de la Música Original

Randy Thom

Sound Designer, Supervising Sound Editor

Mac Smith

Sound Effects Editor

Dennis Leonard

Supervising Sound Editor

Tom Carlson

Supervising Music Editor

Bob Gordon

Productor

Bruce Anderson

Productor

20th Century Fox

Compañía de Produccion

Blue Sky Studios

Compañía de Produccion

Audrey Geisel

Productor Ejecutivo

Chris Wedge

Productor Ejecutivo

Chris Meledandri

Productor Ejecutivo

Christian Kaplan

Casting

Tim Nordquist

Editor

Thomas Cardone

Dirección Artística

Lizette Vega

Set Designer

Michael Knapp

Set Designer

Guillermo Willie Real

Set Designer

Nash Dunnigan

Set Designer

Jake Parker

Set Designer

Kyle Macnaughton

Set Designer

Cal Brunker

Storyboard Artist

Chris Renaud

Storyboard Artist

William H. Frake III

Storyboard Artist

Martin Fuller

Storyboard Artist

Eric Favela

Storyboard Artist

Jeff Biancalana

Storyboard Artist

Tony Maki

Storyboard Artist

Rafael Zentil

Storyboard Artist

Jony Chandra

Storyboard Artist

Karen Disher

Storyboard Artist

Moroni Taylor

Storyboard Artist

Jeff Siergey

Additional Storyboarding

Edmund Fong

Additional Storyboarding

Crystal Chesney

Additional Storyboarding

Frank Marino

Additional Storyboarding

Stephanie Arnett

Additional Storyboarding

Rich Moore

Additional Storyboarding

Wilbert Plijnaar

Additional Storyboarding

Chris Gilligan

Additional Storyboarding

J.G. Quintel

Additional Storyboarding

Paul Downs

Animation

Barry E. Jackson

Visual Development

Jamie Kirschenbaum

Senior Visual Effects Supervisor

Alen Lai

Senior Visual Effects Supervisor

Rhett Collier

Senior Visual Effects Supervisor

Simon Brown

Senior Visual Effects Supervisor

Jeannine Berger

Post Production Supervisor

Tansal Arnas

Schedule Coordinator

Arun Ram-Mohan

Lighting Artist

David Esneault

Lighting Director