 | Kent Rogers als Horton / Peter Lorre Fish (voice) (uncredited) |
 | Sara Berner als Maysie / Baby (voice) (uncredited) |
 | Mel Blanc als Mouse / Hunters / Audience Member (voice) (uncredited) |
 | Frank Graham als Narrator (voice) (uncredited) |
 | Robert Clampett als Various (voice) (uncredited) |
| Dr. Seuss | Novel |
| Robert Clampett | Director |
| Leon Schlesinger | Producer |
| Carl W. Stalling | Music |
