Horton Hears a Who Cast

Voice Cast

About Horton Hears a Who!

Horton Hears a Who! is the third Dr. Seuss book to be adapted into a full-length animated feature film. Produced by Blue Sky Studios, the film was a massive commercial success, earning over $297 million worldwide.

The film features an all-star voice cast, with Jim Carrey and Steve Carell leading the ensemble. The animation brought Dr. Seuss's distinctive artistic style to life while expanding the story for a feature-length format. The film's message about the importance of every individual, no matter how small, resonated with audiences of all ages.

About Horton Hears a Who

Horton Hears a Who is a computer-animated family film adapted from the Dr. Seuss book of the same name. It follows Horton the elephant, who hears a tiny voice coming from a speck of dust and becomes convinced there is an entire civilisation living on it.

Adaptation approach

The film expands the picture book into a feature-length story by adding more incident around Horton's effort to protect the speck and around the parallel world of the Whos, particularly the Mayor of Whoville and his family. The visual design borrows the silhouettes and soft palettes of the Seuss illustrations and translates them into 3D animation that keeps the originals' tactile feel.

Voice cast

Jim Carrey voices Horton, with Steve Carell as the Mayor of Whoville, Carol Burnett as the Sour Kangaroo, Will Arnett, Seth Rogen, Isla Fisher, and Amy Poehler in supporting roles, and Jonah Hill as one of the Mayor's children. The voice ensemble draws heavily from working comedy actors of the period.

Production

Horton Hears a Who was produced by Blue Sky Studios for 20th Century Fox. It was released in 2008 and became a sustained family-film catalogue title. The film is widely used as an introduction to Dr. Seuss material for younger viewers, alongside more recent screen adaptations.

Where to watch

Horton Hears a Who is available to rent or buy on major digital storefronts and rotates through family-tier streaming services depending on Disney's licensing of the former Fox catalogue.

Related cast pages

Family-film viewers often follow up with the How to Train Your Dragon (2025) cast and the Wicked cast.

How to read this cast page

Cast lists work best as a quick reference rather than a transcript of the credits. The principal cast section above lists the actors most viewers will recognise from marketing and from the first episode or first act. The character each actor plays is shown alongside the name, with short relationship cues where they help.

Recurring versus principal cast

Television in particular distinguishes between “series regulars,” who appear in most episodes, and “recurring” or “guest” performers who appear only in some. Recurring cast can shift between seasons: someone introduced as a guest can be promoted to a regular role if the writers decide the character should stay. When that has happened on this title, we update the cast list rather than leave outdated billing in place.

Why character descriptions stay short

We keep character notes brief and free of spoilers. Late-season twists, deaths, and identity reveals are part of why audiences watch a show or a film, and a cast page that gives them away in the first paragraph is harder to use casually. If something is essential to introducing a character — a job, a family relationship, a faction — we include it; otherwise we leave it out.

Spelling and credits

Names are written here the way the production credits them. Where actors are credited differently in different markets, we use the credit listed in the production's official press notes. Stage names, mononyms, and special characters are preserved.

Suggesting changes

If you spot a name we have wrong, a character description that has gone out of date after a new season, or a credit that is missing, the contact page explains how to reach us. We update individual cast pages rather than rewriting the site, so corrections we receive turn into changes on this page directly.