| Dub Taylor | Digger (voice) |
| Bernard Fox | The Chairman (voice) |
| John Fiedler | Owl (voice) |
| Pat Buttram | Luke (voice) |
| George Lindsey | Rabbit (voice) |
| Candy Candido | Brutus / Nero (voice) (uncredited) (unconfirmed) |
| Jeanette Nolan | Ellie Mae (voice) |
| John McIntire | Rufus (voice) |
| Eva Gabor | Miss Bianca (voice) |
| Robie Lester | Miss Bianca (singing voice) (uncredited) |
| James MacDonald | Evinrude (voice) (as James Macdonald) |
| Bob Newhart | Bernard (voice) |
| Geraldine Page | Madame Medusa (voice) |
| Joe Flynn | Mr. Snoops (voice) |
| Jim Jordan | Orville (voice) |
| Michelle Stacy | Penny (voice) |
| Larry Clemmons | Gramps (voice) |
| Bill McMillian | T.V. Announcer (voice) (as Bill McMillan) |
| Ruth Buzzi | German Mouse (voice) (uncredited) (unconfirmed) |
