Once upon a time, Belle and the Beast united all the Disney fairy tale kingdoms in an idyllic land called Auradon. To ensure peace in Auradon, villains and their sidekicks were banished to the Isle of the Lost, a wretched, magic-free island. Separated by a magical portal, the citizens lived isolated from each other for many years.
Twenty years later, in present day Auradon, Ben - the teenaged son of Belle and the Beast - prepares a speech for his upcoming coronation ("Better Together - Prelude 1"). Ben reveals his first official decree to his parents: the children on the Isle of the Lost will come to live in Auradon. As a test run, Ben has chosen the children of Maleficent, Evil Queen Grimhilde, Jafar, and Cruella De Vil to leave the Isle to attend Auradon Prep. Terrified of this plan, Belle and the Beast tell their son that this will be his one chance to bring villains into their world; if it fails, the portal between the two worlds will be closed forever.
On the Isle of the Lost, Mal, Evie, Jay, and Carlos - the troublemaking teenaged offspring of those four infamous villains - receive their invitation to leave the Isle to attend school in Auradon. Mal, the leader of the pack, ensures her friends they can stay on the Isle, where they rule the streets ("Rotten to the Core").
Maleficent, Jafar, Grimhilde, and Cruella arrive to discuss the news with their children. Maleficent identifies an opportunity for revenge: If their children are released into Auradon, they can help the villains take over the free world. Maleficent persuades Mal to go to Auradon, steal Fairy Godmother's wand, and use it to open the portal so that they can rule both worlds together ("Evil Like Me"). Mal agrees, and the four friends (the "Evils") step through the portal to Auradon.
In Auradon, the Evils are greeted by the students of Auradon Prep ("Be Our Guest"). Despite their cheery welcome, there is immediate tension between the students and the newcomers. Fairy Godmother, the headmistress, welcomes them to the school, reminding them that magic is illegal on the premises and that they must follow the rules ("Good Is the New Bad - Preprise"). They meet Ben, his girlfriend, Audrey (Sleeping Beauty's daughter), Chad (Cinderella and Prince Charming's son), Doug (Dopey's son), and Jane (Fairy Godmother's daughter).
The Evils briefly pretend to fit in, but surreptitiously return to their troublemaking ways, wreaking havoc in the school hallways ("Good Is the New Bad - Part 1"). Evie has developed a crush on Chad, and tries to get his attention by cheating off her magic mirror in Professor Maurice's Chemistry Class. Tensions between the students and the Evils escalate, as Audrey and Maurice confront Ben about how poorly the Evils are assimilating into society ("Good Is the New Bad - Part 2").
In their dorm room, the Evils craft a plan to steal Fairy Godmother's wand from the Museum of Cultural History. As they sneak out, they are spotted by Fairy Godmother and Jane, who decides to follow them to the museum.
At the museum, Mal recites a spell from her mother's spell book, causing the guard to fall asleep. After a rare moment of indecision ("Evil Like Me - Reprise 1"), Mal grabs for the wand, but a forcefield protects it. Jay attempts to lunge for the wand, setting off the museum alarm. Carlos turns off the security system and the Evils sneak out of the museum uncaught - though followed by Jane.
In Remedial Goodness class, Fairy Godmother allows the Evils to video chat with their parents back on the Isle, who are dreaming about their impending takeover ("Rotten to the Core - Parents' Revenge"). Later, Jay and Carlos join the Tourney team, showing off skills they didn't know they had ("Goal"). Despite their athletic success, the Evils still face difficulties fitting in; Audrey insults Mal, Chad scams Evie into doing his homework, and Jane unsuccessfully attempts to tell a distracted Fairy Godmother about their visit to the museum. In spite of this, some Auradonians begin to appreciate the newcomers ("Good Is the New Bad - Reprise 1").
Ben visits the Evils in their dorm room, and Mal tries to get information on the wand. Ben tells Mal that his girlfriend will stand with him at the coronation, near Fairy Godmother as she uses her wand to crown him. With a tear from a lonely Jane, the Evils use Mal's spellbook to whip up a batch of love-spelled cookies, crucial to their new plan of making Ben fall for Mal so she can be within arm's reach of the wand at the coronation ("Ways to Be Wicked - Preprise").
Mal offers the potioned cookies to Ben, who instantly falls under the spell, professing his love for her in front of the whole school and inviting her to the coronation ("Did I Mention"). In response, Audrey takes Chad as her new boyfriend, much to Evie's dismay.
On their first date, Mal and Ben share the obligations and pressures of their lives, causing Mal to feel real feelings for him ("Better Together - Prelude 2"). Ben finds Maleficent's spellbook in Mal's bag and explodes in anger, mad at her for disobeying the rules of the kingdom and leaning into her villainous impulses. Mal storms off.
Back in the dorm, Mal announces that she is leaving for the Isle and asks Evie to come with her. Evie admits that, while heartbroken over Chad, she doesn't want to leave Auradon. The best friends promise they will always care for each other, no matter the world they choose ("Space Between"). Mal sets off for the Isle.
When Ben comes looking for Mal, Evie agrees to take him to the Isle to find her, but insists he follow her lead to fit in ("Chillin' Like a Villain"). Meanwhile, back in Auradon, the school erupts in chaos; Audrey and Chad happily tell Ben's parents that the Evils are the cause of the disorder ("Good Is the New Bad - Reprise 2").
Evie, Jay, and Carlos find Mal on the Isle. They reveal that Ben is with them, eager to convince Mal to return to Auradon. Suddenly, Maleficent appears and Mal distracts her, allowing her friends to safely escape. Ben lingers and overhears Mal telling her mother about the love spell and their intent to steal the wand. Torn between two worlds, Ben and Mal wonder what the future holds and what their obligations are to their respective communities ("If Only").
Back in Auradon, Maurice confronts Evie about cheating in class with her magic mirror. Doug, who has developed a crush on Evie, stands up for her, and Maurice agrees to return the mirror if Evie can pass a test without it. Audrey and Chad rile up the Auradonians against Ben and the Evils ("Ways to Be Wicked"). Mal returns to Auradon, and, seeing the way the Evils have been vilified, the foursome commit to their plan to steal the wand.
On the day of the coronation, the Evil Parents watch the proceedings on TV until Maleficent reveals that she plans to rule the world solo - without the other villains. Evie learns she aced her make-up test and invites Doug to the coronation as her date. Meanwhile, Ben admits to Mal that he hasn't been under the effects of the love potion since going to the Isle, where magic doesn't work, and that he truly cares about her.
The coronation commences ("Go the Distance - Chorale") and just as the Fairy Godmother moves to anoint Ben, Jane snatches the wand out of her hand, inadvertently opening the portal between lands. She revels briefly in her power, until Mal snatches the wand, pointing it at the crowd. Ben encourages Mal to make the right choice, but before she can decide her next move, Maleficent bursts through the window and takes the wand from her daughter. As Maleficent points the wand at Ben, Mal realizes her deep feelings of love for him - feelings her mom never showed for her. Maleficent revels in her evilness, towering over the Auradonians ("Evil Like Me - Reprise 2").
Working together, Jay, Carlos, Evie, and Mal use their once-evil plans to steal the wand back from Maleficent. Encanting a spell from memory, they cause Maleficent to shrink to the size of the love in her heart. Mal returns the wand to Fairy Godmother. Having used their powers for good, the Evils are welcomed fully by the Auradonians ("Better Together"), and Ben declares that the portal between the two worlds shall be opened forever ("Break This Down").