Allan Sherman
The Cat in the Hat (voice)
Daws Butler
Mr. Krinklebein the Fish (voice)
Pamelyn Ferdin
Sally (voice)
Tony Frazier
Boy (voice)
Gloria Camacho
Mother (voice)
Thurl Ravenscroft
Thing 1 (voice)
Gene Morford
Thing 2 (voice) (as Lewis Morford)