The film opens with the circus moving to a new town, via the railroad. On the train, Mrs. Jumbo is given her baby, via a stork. She names him Jumbo Jr. but once the female elephants saw his big ears, and how he tripped over them, they renamed him Dumbo… and it stuck.
At their new destination, Dumbo is ridiculed and teased by some boys. Unable to bear seeing her son treated so poorly, Mrs. Jumbo reacts and is later locked up in solitary confinement for misbehaving.
Alone, and frightened, Dumbo remains in the train car and is shunned by the other female elephants who cannot control their constant taunting and snide remarks.
Overhearing the cruelty bestowed upon Dumbo, Timothy, the mouse, frightens the female elephants, then befriends Dumbo. Together, they're determined to change the way everyone sees Dumbo, but not without a few mishaps along the way…
When Dumbo's oversized ears cause a circus performance to go array, he is demoted to "elephant clown"—which makes him very depressed. To cheer him up, Timothy takes Dumbo to see his mother.
After leaving his mother, Dumbo develops a case of hiccups so Timothy takes him to get a drink of water. Only the water is filled with Champagne and they don't know it. After getting a little tipsy, the two begin to see dancing, pink elephants and pass out. When they awake, they discover their up in a tree.
It's then that Timothy realizes Dumbo's unique talent; only Dumbo is too afraid to try flying again.
Determined that this is the skill Dumbo needs to become a star, Timothy enlists the help of a couple of crows and gives Dumbo a magic feather that's supposed to help him fly. With his newfound confidence, Dumbo flies!
Later, during a circus performance where Dumbo is supposed to jump from a burning building, he loses the feather and becomes frightened. Timothy reassures him that everything is going to be okay by coming clean about its non-existent magical powers.
Dumbo successfully makes the dive, then flies around the circus tent as the audience looks on in complete and utter amazement.
The circus owners are so excited about Dumbos newfound stardom that they give Dumbo his own private train car, and lets his mother out of solitaire confinement.