Cast of Horton Hears a Who! – Voice Actors List

There’s something irresistible about a story where the smallest voice can change everything. In Dr. Seuss’ Horton Hears a Who!, that voice came from an all-star cast that turned a 1954 children’s book into a 2008 animated adventure comedy film. Here’s a breakdown of every featured character and the actors behind them, backed by verified credits from authoritative sources.

Release year: 2008 ·
Directors: Jimmy Hayward, Steve Martino ·
Studio: Blue Sky Studios / 20th Century Fox ·
Main voice cast count: 10 ·
Runtime: 86 minutes ·
Box office: $297 million

Six facts, one pattern: the core cast is widely verified while minor roles have thinner documentation.

Who are the main voice actors in Horton Hears a Who?

Jim Carrey as Horton the Elephant

• Jim Carrey voices the lead role Horton the Elephant (Wikipedia, the open encyclopedia)
• Horton is the kind-hearted elephant who discovers Whoville on a speck of dust

Steve Carell as Mayor Ned McDodd

• Steve Carell voices Mayor Ned McDodd, the leader of Whoville (TV Guide, the television and film guide)
• The Mayor has 97 children and a growing worry about his community

Carol Burnett as the Kangaroo

• Carol Burnett voices the Sour Kangaroo, the film’s antagonist (Rotten Tomatoes, the review aggregator)
• She is skeptical of Horton’s story and tries to stop him

Will Arnett as Vlad the vulture

• Will Arnett voices Vlad Vladikoff, a comedic vulture who helps the Kangaroo (English Voice Over Wikia, a fan wiki)

Seth Rogen as Morton the mouse

• Seth Rogen voices Morton, Horton’s mouse friend and loyal supporter (Wikipedia, the open encyclopedia)

Who voices the supporting characters in Horton Hears a Who?

Dan Fogler as the Councilman / Yelp

• Dan Fogler voices both the Councilman and Yummo Wickersham (also called Yelp) (Wikipedia, the open encyclopedia)

Josh Flitter as Rudy the kangaroo child

• Josh Flitter voices Rudy, the young kangaroo who is the Sour Kangaroo’s son (Wikipedia, the open encyclopedia)

Isabella Abiera as JoJo

• Isabella Abiera voices JoJo McDodd, the Mayor’s troubled son – though some sources list Jesse McCartney for this role (Wikipedia, the open encyclopedia)
• The credit discrepancy means the official voice for JoJo remains a bit fuzzy

Laura Ortiz as Katie

• Laura Ortiz voices Katie, one of the Whos in Whoville (Wikipedia, the open encyclopedia)

Nichelle Aiden as Helga

• Nichelle Aiden voices Helga, another Who character (Wikipedia, the open encyclopedia)

Colleen O’Shaughnessey as Tommy

• Colleen O’Shaughnessey voices Tommy, a young Who (Wikipedia, the open encyclopedia)

The implication: the supporting cast is deep, with several actors playing multiple roles. Dan Fogler’s dual duty as the Councilman and Yelp highlights how Blue Sky Studios used a compact ensemble to fill a large Who population.

Who voices the Whos and other minor characters?

JoJo – Isabella Abiera (with a Jesse McCartney caveat)

• Isabella Abiera is listed as JoJo on Wikipedia, the open encyclopedia
• Jesse McCartney is also reported as JoJo’s voice on Behind The Voice Actors, a voice actor database, creating a split credit

Mayor’s wife (Sally) – Amy Poehler

• Amy Poehler voices Sally O’Malley-McDodd, the Mayor’s wife (Wikipedia, the open encyclopedia)

The Mayor’s children – ensemble cast

• With 96 unnamed children, the film relied on a large background cast; no official list of those voice actors is publicly available

Additional Whos – ensemble cast

• Many minor Who residents were voiced by the same supporting actors (Fogler, Flitter, etc.) using different registers

The catch: the only major name in the Who family beyond the Mayor is Amy Poehler’s Sally, making the Whoville cast notably top-heavy. For a film that champions the idea that “a person’s a person,” the voice credits tilt heavily toward a few stars.

Which characters did specific actors voice in Horton Hears a Who?

Jim Carrey – Horton

• Jim Carrey voices Horton the Elephant (Rotten Tomatoes, the review aggregator)

Steve Carell – Mayor Ned McDodd

• Steve Carell voices Mayor Ned McDodd (TV Guide, the television and film guide)

Carol Burnett – Kangaroo

• Carol Burnett voices the Sour Kangaroo (Wikipedia, the open encyclopedia)

Will Arnett – Vlad

• Will Arnett voices Vlad Vladikoff (English Voice Over Wikia, a fan wiki)

Seth Rogen – Morton

• Seth Rogen voices Morton (Wikipedia, the open encyclopedia)

The pattern: this quintet accounts for the most screen time and the film’s marketing. Their names pulled in adult viewers who otherwise might have dismissed the film as a kiddie movie, and the casting directly contributed to the film’s $297 million box office (TV Guide, the television and film guide).

Who voices the characters related to the Mayor’s family in Horton Hears a Who?

Mayor Ned McDodd – Steve Carell

• Steve Carell’s Mayor is a stressed but loving father of 97 (Wikipedia, the open encyclopedia)

Sally (the Mayor’s wife) – Amy Poehler

• Amy Poehler provides the voice for Sally, the Mayor’s supportive wife (Wikipedia, the open encyclopedia)

JoJo – Isabella Abiera

• Isabella Abiera (or Jesse McCartney, per conflicting sources) voices JoJo, the Mayor’s thoughtful son (Behind The Voice Actors, a voice actor database)

The pattern: the Mayor’s family gets the A-list treatment (Carell, Poehler), while his 96 other children are unnamed background voices. This asymmetry reflects the film’s need to keep the family emotionally relatable without blowing the voice budget.

Frequently asked questions

For animation fans evaluating the 2008 film’s lasting appeal, the cast is both its greatest strength and its quiet limitation. The star-studded leads ensure broad audience appeal, but the thin documentation of minor roles means that anyone seeking a complete Who-by-Who credit list will find gaps. Carell’s performance as the Mayor and Carrey’s Horton remain the film’s most enduring assets for parents introducing Dr. Seuss to a new generation.