Kathy Najimy as Kathy Lane

Matt Frewer as The Cat in the Hat

Christopher Lloyd as Mr. Hunch

Patrick Stewart as Sergeant Mulvaney

Billy Crystal as The Voice of America (voice)

Robin Williams as The Father

Howie Mandel as Sam-I-Am (voice)

Andrea Martin as The Ad Woman

David Paymer as The Ad Man

J.D. Daniels as Marco (segment "Mulberry Street")

Eileen Brennan as The Who-Villain

Graham Jarvis as The Farmer

Brady Bluhm as Marco (segment "McElligot's Pool")

Andraé Crouch as Yertle

Bright Eyes as Mack

Maxi Anderson as Turtle Choir Member

Troy Burgess as Turtle Choir Member

Reggie Burrell as Turtle Choir Member

Rick Charles as Turtle Choir Member

Sandra Crouch as Turtle Choir Member

Kristle Murden as Turtle Choir Member (as Kristle Edwards)

Voncielle Faggett as Turtle Choir Member

David Gibson as Turtle Choir Member / Green Eggs and Ham Player

Tammie Gibson as Turtle Choir Member

Kathy Hazzard as Turtle Choir Member

Linda McCrary as Turtle Choir Member

Gene Montoya as Turtle Choir Member / Green Eggs and Ham Player

Kim O'Kelley as Turtle Choir Member

Alfie Silas as Turtle Choir Member

Kevin Stea as Turtle Choir Member

Bambi Swayze as Turtle Choir Member

Jonathan Webb as Turtle Choir Member

Zelda Williams as Daughter

Eleanor Columbus as Daughter

Raymond Del Barrio as Green Eggs and Ham Player

T.J. Espinoza as Green Eggs and Ham Player

Susan Lonergan as Green Eggs and Ham Player

Terry Lindholm as The Onceler

Kay E. Kuter as Dr. Seuss (voice)

Frank Welker as Additional Voice Overs (voice)

Malachi Pearson as Additional Voice Overs (voice)

Winston Churchill as Self - at Potsdam (archive footage) (uncredited)

Charles Durning as (voice) (uncredited)

June Foray as (voice) (archive footage) (uncredited)

Rudolf Hess as Self - with Hitler in Nuremberg (archive footage) (uncredited)

Adolf Hitler as Self (archive footage) (uncredited)

Bob Holt as (voice) (archive footage) (uncredited)

Boris Karloff as (voice) (archive footage) (uncredited)

William D. Leahy as Self - at Potsdam (archive footage) (uncredited)

Vyacheslav Molotov as Self - at Potsdam (archive footage) (uncredited)

Dr. Seuss as Self (archive footage)

Joseph Stalin as Self - at Potsdam (archive footage) (uncredited)

Julius Streicher as Self - with Hitler in Nuremberg (archive footage) (uncredited)

Paul Winchell as (voice) (archive footage) (uncredited)