Maleficent is a powerful fairy living in the Moors, a magical forest realm bordering a human kingdom. As a child, she meets a human peasant boy named Stefan, and they fall in love with each other. However, as they get older, the two grow apart, with Stefan's love being overshadowed by his ambition to be a king, while Maleficent becomes the protector of the Moors.
When King Henry, the ruler of the human kingdom, attempts to conquer the Moors, Maleficent mortally wounds him, forcing his retreat. On his deathbed, Henry declares that whoever kills Maleficent will be named his successor and marry his daughter Leila. Stefan visits Maleficent in the Moors and drugs her, but cannot bring himself to kill her. He instead cuts off her wings, presenting them to Henry as "proof" of her death. While still processing the betrayal, Maleficent saves Diaval, a trapped raven, from being killed by a farmer by turning him into a human. Diaval offers her his service, and brings her news of Stefan's coronation. Furious to learn why her wings were taken, Maleficent, and the Moors she protects, becomes dark and bitter.
Some time later, Diaval informs Maleficent about the christening of Stefan's newborn daughter, Aurora. Maleficent arrives uninvited and curses the infant princess, declaring that by her sixteenth birthday, she will prick her finger on the spindle of a spinning wheel and fall into an eternal sleep. Maleficent mocks Stefan's plea for mercy, but offers an antidote – the curse can be broken by true love's kiss, which she and Stefan both believe does not exist. Stefan orders three pixies, Knotgrass, Flittle, and Thistlewit, to hide and protect Aurora in a forest cottage until the day after her sixteenth birthday. He also destroys every spinning wheel in the kingdom, hiding their remnants in the castle dungeon; he then sends his armies to find and kill Maleficent, but she surrounds the Moors with a wall of thorns. Over the years, Stefan grows obsessed with killing Maleficent and gradually loses his sanity, even refusing to see his own wife on her deathbed.
Meanwhile, Maleficent and Diaval watch Aurora grow from afar, and secretly begin to take over care of her from the incompetent pixies. After several face-to-face encounters with Maleficent, whom she believes to be her "fairy godmother", Aurora bonds with her and starts to regularly visit the Moors. Realizing she hasn't the heart to hurt Aurora, Maleficent privately and unsuccessfully attempts to revoke the curse, forgetting that she stated "no power on earth" can do so. Some time later, Aurora meets Philip, a prince from the neighboring kingdom, and both are mildly attracted to each other.
On the day before her sixteenth birthday, Aurora gains Maleficent's permission to live in the Moors. When she informs the pixies of this, they reveal the truth about Aurora's lineage and the curse. Heartbroken, Aurora rides off to her father's castle. Instead of welcoming her, Stefan, still plotting to kill Maleficent, locks her in a room. The curse's power draws Aurora to the dungeon, where she pricks her finger on a spindle and falls into a deep slumber. Hoping to save her, Maleficent and Diaval abduct Philip and infiltrate Stefan's castle. The pixies encourage the reluctant Philip to kiss Aurora, but this does not wake her. After they leave, Maleficent tearfully apologizes to Aurora and kisses her on the forehead. This unexpectedly wakes Aurora, as Maleficent truly feels maternal love for her.
As Maleficent, Aurora, and Diaval attempt to leave, Stefan and his guards ambush them. Maleficent transforms Diaval into a dragon to help her, but both are subdued. Aurora finds and releases Maleficent's caged wings, which reattach themselves to their mistress, allowing her to fight back. Maleficent drags Stefan to the top of a tower; unwilling to kill him, she announces the fight is over and turns to go. Stefan tackles her from behind, dragging them both off the tower; she opens her wings to save herself, and he loses hold and falls to his death. With Stefan gone, Maleficent returns the Moors to their former glory and crowns Aurora their new ruler, uniting the two kingdoms. Aurora also starts a relationship with Philip.
