The Wizard of Oz is a 1939 American musical film directed by Victor Fleming (and others) from a script to which Noel Langley, Florence Ryerson and Edgar Allan Woolf contributed, based on the 1900 children's novel The Wonderful Wizard of Oz by L. Frank Baum, with fantasy elements.

On her way to the city, Dorothy meets a Scarecrow (Ray Bolger) with no brain, a Tin Man (Jack Haley) with no heart and a Cowardly Lion (Bert Lahr), all of whom are portrayed by the same actors as the farm hands back in Kansas. The three decide to accompany Dorothy to the Wizard in hopes of obtaining their desires.

Along the way, they behave in various ways which demonstrate that they already have the qualities they think they lack: the Scarecrow has several good ideas, the Tin Man is kind and sympathetic and the Lion is ready to face danger even though he is terrified. The group reaches Emerald City, where they are greeted kindly. The group talks to the Wizard of Oz, a disembodied and imposing head, formed out of steam from a giant cauldron, with a booming voice, who says that he will consider granting their wishes if they can bring him the broomstick of the Wicked Witch. The group is terrified, since this will involve killing the Witch in order to get the broom.

On their way to the witch's castle, they are attacked by a gang of flying monkeys who carry Dorothy and Toto away and deliver her to the witch. The Witch demands that Dorothy hand over the ruby slippers. After the witch threatens to drown Toto in the river, Dorothy agrees to give her the shoes, but a shower of sparks prevents their removal. The witch says that the shoes cannot be removed unless Dorothy dies. While the witch is distracted, Toto takes the opportunity to escape. The witch then locks Dorothy in a chamber and leaves to consider how to kill Dorothy without damaging the shoes' magic. Toto finds Dorothy's friends and leads them to the castle. After disguising themselves in the castle guards' uniforms, they enter the citadel where they free Dorothy and attempt an escape. The witch and her Winkie soldiers corner the group on a parapet, where the witch sets the Scarecrow's arm on fire. To douse the flames, Dorothy throws water on them while accidentally splashing water on the horrified witch, causing her to melt. To the group's surprise, the soldiers are delighted. Their captain (Mitchell Lewis) gives Dorothy the broomstick in gratitude as the heroes begin their journey back to the Emerald City.

Upon their return to Emerald City, the Wizard is reluctant to grant the group their wishes. Toto exposes the great and powerful wizard as a fraud; they find an ordinary man hiding behind a curtain operating a giant console which contains a group of buttons and levers. They are outraged at the deception, but the wizard solves their problems through common sense and a little double talk rather than magic. He explains that they already had what they had been searching for all along and only need things such as medals and diplomas to confirm that someone else recognizes it.

The wizard explains that he, too, was born in Kansas and his presence in Oz was the result of an escaped hot air balloon (although his balloon says Omaha, which is a city in the neighboring state of Nebraska). He promises to take Dorothy home in the same balloon, leaving the Scarecrow, Tin Man and Lion in charge of Emerald City. Just before takeoff, Toto sees a cat and jumps out of the balloon's basket. Dorothy jumps out to catch him and the wizard, unable to control the balloon, leaves without her. She is resigned to spend the rest of her life in Oz until Glinda appears and tells her that she has always had the power to return home, through the power of the ruby slippers. Glinda explains that she did not tell Dorothy at first because she needed to find out for herself that she doesn't need to run away to find her heart's desire.

Dorothy says a tearful goodbye to the friends she has met in Oz and then follows Glinda's instructions to get home, which consist of closing her eyes, tapping her heels together three times and chanting "There's no place like home." The film returns to sepia tone and Dorothy awakens in her bedroom in Kansas (still chanting "There's no place like home," in her sleep) surrounded by family and friends and tells them of her journey. Everyone laughs and tells her it was all a dream, except Uncle Henry, who says sympathetically, "Of course we believe you, Dorothy." Toto appears and jumps onto the bed. A happy Dorothy, still convinced the journey was real, hugs Toto and says one last time, "There's no place like home."