Walt Disney's distributor, RKO Radio Pictures, had qualms about releasing this 64-minute feature as a major motion picture. They tried to persuade Disney to either cut it to short-subject length, extend it to at least 70 minutes, or have it released as a B picture. Disney stood his ground, and the film was released as an A picture as Disney intended.
Joe Grant and Dick Huemer changed Dumbo's mother's name from "Mother Ella" to "Mrs. Jumbo" as a reference to the famed Barnum & Bailey circus pachyderm.
A sequel direct to video/DVD titled Dumbo 2 was announced back in he early 2000s. With a story that takes place after the original involving Dumbo and a group of young circus animals got separated from the WDP Circus and try to find their way back to the circus. This proposed idea appeared to have been canceled with no more than storyboards and animated drawing sheets being made during preproduction.
A very tightly budgeted, scripted, and produced film, because Walt Disney needed the film to bring in much-needed revenue after the expensive failures of Pinocchio and Fantasia. Final negative cost of Dumbo was $813,000 (making it the least expensive of all Disney's animated features), and it grossed over $2.5 million in its original release (more than Pinocchio's and Fantasia's original grosses combined).
Casey Junior made his first appearance in footage that appeared in The Reluctant Dragon when Robert Benchley is touring the sound effects department. The version is slightly different and much longer.
Cels for Dumbo are the rarest in the industry. The animators, after the scene was safely "in the can", would strew the used cels in the corridors and go sliding on them. In addition the gray paint (used for so many of the elephant skins) would "pop" when the cel was flexed. Many irreplaceable cels were destroyed this way.
During production there was a long and bitter animators strike, in which half of the studio's staff walked out. Some of the strikers are caricatured as the clowns who go to "hit the big boss for a raise".
Entered into the 1947 Cannes Film Festival.
In December 1941, Time magazine planned to have Dumbo on its cover to commemorate its success, but it was dropped due to the attack on Pearl Harbor.
Initially Walt Disney was uninterested in making this movie. To get him interested, story men Joe Grant and Dick Huemer wrote up the film as installments which they left on Walt's desk every morning. Finally, he ran into the story department saying, "This is great! What happens next?"
Mrs Jumbo (Dumbo's mother) only speaks once when she says Dumbo's original name.
The film was originally planned as a 30-minute featurette before Walt Disney assigned one of his producers, Ben Sharpsteen, to expand the idea into a feature.
The first Disney animated feature (and still one of the very few) to be set in America.
The first Disney movie for Sterling Holloway (the Stork) and Verna Felton (the Elephant Matriarch). Both would become regulars in Disney animated films for the next thirty-five years.
The name of the circus (seen on a sign as the train leaves the winter headquarters) is WDP Circus (Walt Disney Productions).
The only Disney animated feature film that has a title character who doesn't speak.
The shadow that Timothy Mouse casts on the ringmaster shortly before he turns himself into a ghost was inspired by Nosferatu, eine Symphonie des Grauens.
The vocals for the song Baby Mine were performed by Betty Noyes, the same singer who dubbed Debbie Reynolds' singing in two numbers in Singin' in the Rain.
There's a reference to "The Little Engine That Could". While Casey Jr. is trying to get up a hill, the train sounds like it's talking. It says "I think I can, I think I can." Then when the train gets up the hill and starts going faster, it changes to, "I thought I could, I thought I could."
This film and Snow White and the Seven Dwarfs are the only classic Disney films to use watercolored backgrounds (they were used in this film because they were cheaper than the gouache and oils used for Pinocchio and Bambi) and the last time they were used until Fantasia/2000.