Horton

Jim Carrey

Horton

Giannis Zouganelis

Horton

Michiel Huisman

Burgemeester Ned

Filemon Wesselink

Mayor of Who-ville

Ilias Zervos

Mayor of Who-ville

Steve Carell

Narrator

Giannis Kotsiras

Kangaroo (voice)

Carol Burnett

Salley O'Malley

Amy Poehler

Kangeroe

Lenette van Dongen

Vlad

Marcel Jonker

Vlad (voice)

Will Arnett

JoJo (voice)

Jesse McCartney

Kangaroo

Natasa Asiki

Morton (voice)

Seth Rogen

Morton

Petros Damoulis

Dr. Larue

Isla Fisher

Jo Jo

Dimitris Dimopoulos

Yummo

Dan Fogler

Tommy (voice)

Jonah Hill

Mrs. Quilligan (voice)

Jaime Pressly

Narrator (voice)

Charles Osgood

Rudy (voice)

Josh Flitter

Jessica

Laura Ortiz

Miss Yelp (voice)

Niecy Nash

Katie (voice)

Joey King

Hedy / Hooly (voice)

Shelby Adamowsky

Old Time Who (voice)

Jack Angel

Caitlin Rose Anderson

Heather (voice)

Emily Anderson

Town Cryer (voice)

Jan Rabson

Who (voice)

John Cygan

Another Who (voice)

Jess Harnell

Who Mom (voice)

Debi Derryberry

Samantha Raye Droke

Hildy / Holly (voice)

Samantha Droke

Who Kid (voice)

Karen Disher

Wickersham Guard 1 (voice)

Marshall Efron

Willie Bear (voice)

Bill Farmer

Joe (voice)

Jason Fricchione

Who Girl (voice)

Heather Goldenhersh

Helga (voice)

Selena Gomez

James Hayward

Obnoxious Who (voice)

Jimmy Hayward

Christina Martino

Glummox Mom (voice)

Laraine Newman

Hanna (voice)

Ellie Martino

Wickersham Guard 2 (voice)

Tim Nordquist

Angela (voice)

Colleen O'Shaughnessey

The Dentist (voice)

Joe Pasquale

Christoph Maria Herbst

Who Child #1 (voice)

Connor Anderson

Uwe Büschken

Additional Voices (voice)

Isabella Acres

Additional Voices (voice)

Bob Bergen

Anke Engelke

Additional Voices (voice)

Jeff Biancalana

Klaus-Dieter Klebsch

Bernd Rumpf

Additional Voices (voice)

Madison Davenport

Lutz Schnell

Additional Voices (voice)

Teresa Ganzel

Victoria Sturm

Additional Voice (voice)

Kathy Graves Toon

Additional Voices (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

Jojo (singing voice) (uncredited)

Fletcher Sheridan