Dorothy is a young orphaned girl raised by her Uncle Henry and Aunt Em in the bleak landscape of a Kansas farm. She has a little black dog Toto, who is her sole source of happiness on the dry, gray prairies. One day the farmhouse, with Dorothy and Toto inside, is caught up in a tornado and deposited in a field in Munchkin Country, the eastern quadrant of the Land of Oz. The falling house kills the evil ruler of the Munchkins, the Wicked Witch of the East.
The Good Witch of the North comes with the Munchkins to greet Dorothy and gives Dorothy the silver shoes (believed to have magical properties) that the Wicked Witch had been wearing when she was killed. In order to return to Kansas, the Good Witch of the North tells Dorothy that she will have to go to the "Emerald City" or "City of Emeralds" and ask the Wizard of Oz to help her. Before she leaves, the Good Witch of the North kisses her on the forehead, giving her magical protection from trouble.
On her way down the road of yellow bricks, Dorothy frees the Scarecrow from the pole he is hanging on, restores the movements of the rusted Tin Woodman with an oil can, and encourages them and the Cowardly Lion to journey with her and Toto to the Emerald City. The Scarecrow wants to get a brain, the Tin Woodman a heart, and the Cowardly Lion, courage. All four of the travelers believe that the Wizard can solve their troubles. The party finds many adventures on their journey together, including overcoming obstacles such as narrow pieces of the yellow brick road, vicious Kalidahs, a river, and the Deadly Poppies.
When the travelers arrive at the Emerald City, they are asked to wear green spectacles by the Guardian of the Gates as long as they remain in the city. The four are the first to ever successfully meet with the Wizard. When each traveler meets with the Wizard, he appears each time as someone or something different. To Dorothy, the Wizard is a giant head; the Scarecrow sees a beautiful woman; the Tin Woodman sees a ravenous beast; the Cowardly Lion sees a ball of fire. The Wizard agrees to help each of them--but only if one of them kills the Wicked Witch of the West who rules over the western Winkie Country. The Guardian of the Gates warns them that no one has ever managed to harm the very cunning and cruel Wicked Witch.
As the friends travel across the Winkie Country, the Wicked Witch sends wolves, crows, bees, and then her Winkie soldiers to attack them, but they manage to get past them all. Then, using the power of the Golden Cap, the Witch summons the Winged Monkeys to capture Dorothy, the Cowardly Lion and Toto, and to destroy the Scarecrow and the Tin Woodman.
When the Wicked Witch gains one of Dorothy's silver shoes by trickery, Dorothy in anger grabs a bucket of water and throws it on the Wicked Witch. To her shock, this causes the Witch to melt away, allowing Dorothy to recover the shoe. The Winkies rejoice at being freed of the witch's tyranny, and they help to reassemble the Scarecrow and the Tin Woodman. The Winkies love the Tin Woodman, and they ask him to become their ruler, which he agrees to do after helping Dorothy return to Kansas.
Dorothy, after finding and learning how to use the Golden Cap, summons the Winged Monkeys to carry her and her companions back to the Emerald City. and the King of the Winged Monkeys tells how he and the other monkeys were bound by an enchantment to the cap by the sorceress Gayelette.
When Dorothy and her friends meet the Wizard of Oz again, he tries to put them off. Toto accidentally tips over a screen in a corner of the throne room, revealing the Wizard to be an ordinary old man who had journeyed to Oz from Omaha long ago in a hot air balloon. The Wizard has been longing to return to his home and be in a circus again ever since.....