A beautiful tiny girl grows from a barleycorn which has been enchanted by a witch. She is found when a woman kisses the petal on the flower. The woman names the girl Thumbelina.
Thumbelina is soon kidnapped by a toad who wants her to marry her son, and she is deposited on a lily pad.
Fish rescue Thumbelina by gnawing at the lily pad, and she floats downstream, where she is lifted up by a large beetle. The beetle soon abandons her after his fellow beetles convince him that she is ugly because she is not like them.
Winter comes, and Thumbelina is stranded and lost in the snow-covered forest. A friendly field mouse finds her and takes her into her home. The mouse's neighbour, an old mole, falls in love with Thumbelina because of her beautiful singing voice. He leads Thumbelina along a passage towards his house, where they find a swallow that the mole pronounces to be dead. Thumbelina returns later to discover that the bird is not dead.
Thumbelina climbs on to the swallow's back, and they fly away to the land of the flower people, where they meet the Prince, whom Thumbelina marries.