Mal (Dove Cameron), Evie (Sofia Carson), Carlos De Vil (Cameron Boyce), and Jay (Booboo Stewart) return to the Isle of the Lost to recruit a new batch of new villainous offspring to join them at Auradon Prep. When a barrier breach jeopardizes the safety of Auradon during their departure off the isle, Mal resolves to permanently close the barrier, fearing that nemeses Uma (China Anne McClain) and Hades (Cheyenne Jackson) will wreak vengeance on the kingdom. Despite the decision, an unfathomable dark force threatens the people of Auradon, and it's up to Mal and the VKs to save everyone in their most epic battle yet.
There is a pre and post-credit scene dedicated to Carlos's actor, the late Cameron Boyce.
VK Day has arrived, with Mal, Evie, Jay, and Carlos returning to the Isle of the Lost to choose a new quartet of kids to attend Auradon Prep the next semester. The Isle has also been adorned with posters of the original VKs to inspire the good and hope in the children, along with roads and alleys renamed after them as well to honor their success. Leading the children of the island in the song "Good to Be Bad", the original VKs lead the crowd of kids and their guardians to a gathering for the announcement. Evie, Carlos, Jay, and Mal choose Dizzy Tremaine, Squeaky and Squirmy Smee, and Celia Facilier as the kids to go. They inform them that they will be back in one week for them, telling them playfully to only pack things belonging to them.
A week later, Mal is watching the coast through a telescope at Auradon Prep. She is surprised by Ben, whom she confides in that she worries that Uma will return for revenge the moment they drop their guard. However, Ben reassures Mal by promising to post more guards on the lookout for Uma. They head for the front lawn, where the royal limo will take them, Evie, Jay and Carlos to the Isle for the kids; a crowd has also gathered for the event. Fairy Godmother stops Mal on the platform, much to her confusion. Ben takes a mic, thanking the crowd for attending and that he is happy that the VK integration program has had great success, earning a vague sarcastic quip from Chad Charming on how he met his new girlfriend. Chad is silenced by Ben's ex-girlfriend Audrey, who is bitter over the events that transpired since along with her grandmother Leah. Ben recounts how he and Mal met, reciting a reprise of "Did I Mention", kneeling down; he holds out a box with a golden ring shaped like a dragon with a purple gem in it. He asks Mal if she would marry him, to which she tearfully agrees.
Everyone celebrates, with Carlos even sharing a chest bump with ex-King Beast, only to apologize; Beast tells him that it's okay. A happy Ben talks to Jay, Carlos, and his father about how he's now engaged. Evie tells Mal that Belle had already planned a party for Mal to celebrate. Mal shares hugs with Beast and Belle, who are happy to welcome her into their family. Evie nearly tells Doug "I love you", but quickly changes the subject out of embarrassment. Amidst the happy crowd, Queen Leah is disappointed in Audrey for failing to secure their family's royal legacy by marrying Ben, only to be given a very bitter retort by her granddaughter. Audrey congratulates Mal, only to remind her about the love spell she used to break them up, so Ben would be free to fall in love with Mal; she sarcastically says it will make a good story for Mal's grandchildren. Unfazed, Mal tells Audrey that there are currently four children waiting for her. Mal, Ben, Evie, and Carlos board a purple limo, which has Mal's name on the license plate; the driver steps out and gives the keys to Jay, who promptly drives the five of them to the Isle of the Lost to collect the kids.
Carlos and Jay help pack Squeaky and Squirmy's bags in the trunk, with the boys saying goodbye to their father. Dizzy is asked by her grandmother, Lady Tremaine, if she remembered everything, to which Dizzy is sure she did, only for her granny to hand her the glue gun she left behind. Lady Tremaine wonders what Dizzy will do without her to look out for her, to which Dizzy responds with a hug, surprising her. Dizzy gets in the limo, along with Evie. Mal offers to help Celia put her stuff in the limo, only to be ignored as Celia does it herself. With all the VKs in the limo, Mal and Ben shut the trunk and get in as well. As the limo drives off, Jay notices one of the Smee twins is holding onto his arm with a firm grip; he asks if the boy plays sports. In the back, Carlos tries to calm the other twin by offer him some chocolate candy. Dizzy talks to Evie about excited she is to live with her in Evie's castle; Evie says its only a starter castle. Celia offers to tell Ben's fortune, which he accepts; she tells him that he will be a brave and wise king, which Mal says is already true. Celia tells Mal that the cards never lie, being given a generous payment from Ben.
In Auradon, everyone watches the live broadcast of the limo leaving the barrier. Queen Leah states that they should only be opening it to toss Uma back in, not let more villains out, earning disapproving scowls. As the barrier nearly closes, Hades rushes through the crowd and plunges his hand through the hole, preventing it from closing. Evie spots this and tells Jay to stop the limo. In Hades' hand is his source of power, a blue ember, which reignites now outside the barrier. Using its power, Hades pulls the hole open wide enough for himself to escape. Ben, Jay and Carlos attempt to push Hades back in, only for them to stunned by blasts from Hades' ember. Mal transforms into a dragon to confront Hades, only to zapped by the ember. In Auradon, everyone panics. Encouraged by her friends, Mal releases a blast of hot air instead of flames, pushing Hades back into the barrier. A weakened Mal changes back, telling her friends that Hades was attempting to drain her powers. However, she is assured that Hades is now back where he belongs.
At Auradon Prep that night, Audrey is crying in her room. In her diary, she sketches herself as queen, only to realize its a hopeless dream. Deciding that if she can't become the queen of Auradon, she will have to make do with becoming the queen of the villains. Angry with Mal for getting her dream, Audrey breaks into the museum to break the crown meant for Auradon's queen; while the guard falls asleep, she shuts down all the cameras. Finding the crown, Audrey breaks the display case, ready to trash the crown. However, a curtain suddenly pulls away, revealing Maleficent's scepter glowing in the next room. Enticed by the idea of using magic to get revenge, Audrey changes her plan. Donning the crown herself, Audrey uses the scepter's magic to look more villainous, deciding to become the queen of Auradon through evil. ("Queen of Mean")
The next day, Ben, Mal, Beast, Belle and Fairy Godmother met about the near-escape of Hades from the Isle. Beast states Auradon is put at risk every time they open the barrier, listing Maleficent's return, Uma's escape ,and Hades' attempt as examples. Ben's phone receives a text, which tells him about the theft of the crown and scepter. Beast assumes that its Uma that stole them, only to be told by Ben that they don't know if it was Uma; singling Uma out is nothing but paranoia. Belle notes that if this news gets out people will be too afraid to leave their homes, asking Mal what ideas she has. Mal reluctantly decides that closing the barrier for good is the only option they have. Ben is against the idea, as it will trap the remaining VKs. However, Mal reminds him that as king and future queen, they have to ensure the safety of their people.
Later, at Evie's 4 Hearts, a cottage serving as the Vk's residence and Evie's place of business. Mal tells Evie about the plan to close the barrier, but leaves out that it was her idea. Evie points out the same facts as Ben, but Mal manages to convince Evie that it's the best choice. Later, everyone is getting ready to go to Jane's birthday party. However, Carlos notices part of the cake they made for Jane had a part of it missing. Annoyed, he demands to know which of their guests ate it. Outside, is revealed that Celia and Dizzy had been impatient and stolen the cake; they like it better than what they have on the isle, because it lacks dirt and flies. On the other side of the house, Mal steps outside with her gift for Jane, only to be surprised by Audrey, who she is surprised to see having turned evil and carrying her mother's scepter. Mal tries to reason with Audrey, who refuses to listen to her, angry that Mal has gotten the life she wanted; worse, she intends to make Auradon pay for "betraying" her. Audrey zaps Mal with the scepter, turning her into an old hag. The VKs rush outside as Audrey vanishes. Jay suggests Mal uses a spell to reverse what Audrey did, but Mal tells him only Hades' ember is powerful enough to undo the scepter's magic. Celia reveals that she knows where Hades lives, as she used to be his errand rat, getting drafted to help. Evie helps Mal inside for a change of clothes .The VKs ride their bikes to the edge of the land, where Mal recites the spell she previously used to reach the isle.
Audrey arrives at Jane's birthday near the Enchanted Lake, annoyed she wasn't invited. She asks the kids if they truly forgotten what the VKs did to them when they arrived. Before she can go any further, Chad arrives, complimenting her. He asks if she could use a lackey, which she accepts; per his usual suck up attitude, Chad is trying to avoid trouble by allying with whoever is strongest. Audrey sings "Happy Birthday" to Jane, creates a pink mist that starts putting people under a sleeping spell. Jane jumps in the lake to avoid the spell, as Audrey leaves with Chad. Jane calls Ben, updating him on Audrey's villainous turn and the sleeping spell that she's unleashed on Auradon.
Once inside the barrier, everyone parks outside of Dr Facilier's voodoo arcade, where Celia keeps her key to Hades' lair. Mal notices that her youth has been restored, only for Celia to remind her that evil magic is canceled by the barrier. Heading inside, Celia grabs the key and tells her father that she's a big player in a new game; he reminds her to make sure she gets her cut from the deal. Carlos turns on a TV, which shows a broadcast with the reporter stating rumors say Audrey is behind the sleeping spell; however, the reporter thinks it's a lie and wonders which villain is behind the spell. He gets an update that the spell is heading towards him. The rest of the VKs join Carlos, realizing Audrey has made her next move. The VKs go outside, seeing Harry Hook, Gil and two other members of Uma's pirate crew have stolen their motorcycles; Carlos and Jay are annoyed with themselves for not locking up their bikes, due growing relaxed in Auradon. Harry's group takes off, with Jay, Carlos ,and Evie giving chase. Mal stops Celia, reminding her of the importance of the ember. Celia remarks that the time is close to Hades' nap time; swiping the ember should be easy.
Celia leads Mal to the entrance of Hades' lair, which has a screen door covered with junk to create a makeshift visage of a skull. On top of the door written in wooden planks is "GET LOST!". Celia unlocks the door, as Mal notices a "Beware of Dog" sign on the door. Mal wonders how big the door is, to which Celia calmly says Mal will see. They enter the cavern behind the door, hearing barking echo. Celia tells Mal to keep quiet as it echoes very loudly. Taking a bicycle-powered mine cart, they two softly peddle forward to the interior of Hades' home. They stop at a hole in the wall, which leads door some wooden steps to a living area, where Hades is snoring away on a comfy chair. Mal and Celia slowly go down, only for Mal to be startled by the barking. Celia smiles, gesturing to a record player, which has the sound of barking coming from it. Mal is motioned by Celia to take the path behind Hades' chair to sneak up and steal the ember from the table next to him. However, because of how long Mal is taking, Celia abruptly stops the record, waking Hades, who demands to know why she's there. Celia tosses him canned corn, which Hades catches in one hand as Mal grabs the ember; however, he uses his free hand to grab Mal's hand and take the ember back.
Met by Hades' stare, Mal nervously says "Hi Dad", surprising Celia. Hades greets Mal, recalling the show she put on at the barrier; the fight was never a real. Mal retorts Hades could talk about his "escape attempt"; Hades explains that he was only coming to see her. Mal wonders if Hades wanted to see her because she's going to be queen, to which he tells her not to be bitter. Mal bitterly reminds Hades that he abandoned her, to which Hades quickly counters; he left Maleficent, because he couldn't handle living with her. Mal agrees Maleficent isn't easy to deal with, to which Hades says is something they have in common - hatred of Maleficent. However, Mal counters that while her mother is an evil lunatic, she at least raised her. Hades tells Mal to get over it. Mal tells Hades that she came for his ember to break a spell on Auradon. This leads Hades to improvise a song about Mal having a better life without him in it, while Mal sings for him to hand over the ember. ("Do What You Gotta Do") Hades relents and gives Mal the ember, warning that she cannot access all of the ember's powers as she's only "half-Hades". Mal leaves with Celia, whom Mal tells only Evie knows about Hades being her father.
Meanwhile, Ben is trying to think of what to do. He instructs his men to pass out gas masks to those not yet affected by the sleeping spell. He instructs another to see if anyone has found Audrey and if she has a list of demands. The moment Ben sits to try thinking again, Audrey appears behind him. She tells him that her only demand is for "her life" to be returned. She offers to wake everyone up if Ben marries her instead. Seeing Audrey's new look, Ben wonders if someone put a spell on her. However, Audrey states that she is thinking for herself, musing on how she got dumped because she wasn't "bad" enough. Ben tells Audrey he liked her better as she was, because she wouldn't want to hurt Auradon. Ben offers forgiveness for her crimes, angering Audrey, who tells Ben that sleeping is too good for him and zaps him with the scepter; Ben gives off a roar as he falls to the ground. Deciding she's been too lenient with a sleeping spell, Audrey casts a spell that turns everyone not asleep to stone. At the same time, Fairy Godmother had almost reached the museum to get her wand to undo Audrey's sleeping spell; however, she turns to stone just outside.
Back in the isle, Mal and Celia reunite with Carlos, Evie and Jay, who failed to reclaim their bikes. At the barrier, Jay opens it to let them through. The moment she steps out, Mal surges with blue magic from the ember, changing her outfit to have blue leather and her hair to have blue highlights. Evie notices, complimenting the new look, while Carlos states the ember packs a punch. Unseen by them, Harry and Gil wait until the last minute and plunge through the closing hole in the barrier. Both celebrate their escape, stating they wish to go to Auradon for visit. A scuffle ensues, causing Mal to lose grip on the ember as it fails towards the ocean. However, the ember is caught by one of Uma's tentacles; she returns to human form, reuniting with her loyal pirates. After telling Harry and Gil about how much better it is outside, Uma is updated on Audrey's attack. Uma offers the assistance of her crew and the return of the ember so long as Mal uses her authority as queen to allow any VKs who wish to live in Auradon to leave the island. Mal is hesitant to do so, but relents; Evie backs up her word. Evie attempts to diffuse the tension by sharing gum, but no-one is interested.
They arrive on the lawn of Auradon Prep, with Celia awestruck. Seeing everyone is asleep, Gil helps himself to some fruit from a bowl nearby; Jay tries to stop him, until Uma reminds him there's no fresh fruit on the island. Harry attempts to swipe some cash, as "payment" for his help, only to be threatened by Jay. Carlos finds his dog Dude, who tells him Audrey put most of the people to sleep. Evie finds one of the band members, Hannah, who has been turned to stone. Uma wonders where Audrey spends time, but Mal decides that Audrey would go after Ben next. Despite Uma and Mal bickering again, the VKs head for Beast Castle.
At Fairy Cottage (which is the very same cottage Aurora was hidden by Flora, Fauna and Merryweather), Audrey watches the arrival of the VKs from the jewel in Maleficent's scepter. She is not happy to see not only has Mal found a way to restore her youth, but now Uma and her pirates have teamed up with the VKs; now she has both a demi-goddess fairy and a sea witch to deal with. In a hysterical fit, she demands Chad provide answers, despite the fact he has been with her the entire time. Chad offers to find out, but Audrey regains her cool and stops him. She plans to cause some mischief.
At Beast Castle, the VKs look for Ben. As Mal keeps calling out for him, though Jay and Celia suggest he may be asleep or turned to stone; Carlos silences them quickly. Spotting claw marks going through a painting on the wall, everyone becomes worried about what else Audrey could have released. Dude tells the VKs that he's got Ben's scent and heads after it. Gil likes Dude, remembering the closest thing he had to a pet was the elk head in his dad's "man cave". Dude leads them to a room full of suits of armor; Gil wonders if Dude's puppies would be able to talk as well, but is told by Carlos to adopt a rescue if he wants a pet. As Mal and Uma begin arguing over the lack of success, Harry notices a suit of armor looking at them; he stops their arguing just as pink smoke animates all the suits of armor; Audrey's voice comes from the lead suit, laughing that she's sent some knights in place of a prince. The VKs work together to fight off the suits, with Mal and Uma landing blows to a suit and the same time; their combined magic briefly short-circuits Audrey's control. Mal casts a spell to make the armor copy the VKs dance moves before the armor collapses. ("Night Falls")
Everyone celebrates their success, just as Mal and Uma noticed they were enjoying each other's company and quickly go silent again. Frustrated, Evie decides to use an icebreaker; if they compliment something about each other, they can bond better; she compliments Harry's accent. Uma wonders if Evie is always so peppy, only for Mal to get Evie refocused on the task at hand. Uma wonders where Audrey hangs out, to which Evie and Mal remember that Audrey is still in her dorm room for summer school. Harry and Gil quickly crack up at the idea of summer school, something even the Isle doesn't have. Mal asks Jay, Carlos, Harry and Gil to take Dude to look for Ben, while she, Uma, Evie and Celia look in Audrey's room for clues.
In the woods, Gil becomes fascinated by how fruit grows on plants in the wild; he tries the icebreaker, telling Jay how impressed he is with his athletic abilities. Jay returns the compliment by telling Gil that he's amazed by how simple things impress Gil. Gil guesses Jay has seen everything in Auradon and has even eaten a lunch of fruit straight off a bush. Jay tells him that he hasn't, as tourney takes up all his time; Harry laughs at Jay for playing a children's game. However, Harry does concede that the idea of eating fruit from the wild is nice. At Auradon Prep, Uma reads Audrey's diary, laughing at the misery Audrey suffered because of Mal. An annoyed Mal asks Uma if she found out anything useful from the diary, to which Uma reveals that Audrey spends time at Fairy Cottage; Mal notes the irony is not lost on her. The girls return to the VK's house, with Uma impressed. Inside, Dizzy, Squeaky and Squirmy are asleep from the spell. Celia covers them with a blanket and tells Dizzy that soon more VKs will come from the island. Evie finds Doug asleep in her sewing room. Uma and Mal flatly tell Evie to wake him with true love's kiss. Asking to be alone, Evie wonders if what she has with Doug is true love. Deciding that there's only one way to find out, she kisses him and Doug wakes. ("One Kiss") Harry informs Carlos that Dude resumed tracking Ben's scent. This leads them to Ben, who was transformed into a beast by Audrey. Seeing Ben with a splinter in his hand, Carlos calms him long enough to get the splinter out. The following moment, Ben is sprayed by water, which comes from a squirtwand used by Jane. Carlos happily reunites with Jane, while Jay helps a tired and confused Ben sit down. Seeing Ben still has facial hair and fangs, Jane blasts him again with the squirtwand, only for no results; she notes that the Enchanted Lake water can only do so much on its own. Ben is surprised to see Harry and Gil, only to be repeatedly told that he will be told the details on the way back to the VK's house.
Waiting for the boys to return, Mal thanks Uma for help; she now sees the good in her that Ben did. An enraged Audrey decides to stand her ground and wait for the VKs, but when Chad suggests they leave for a new location, she locks him in the broom closet. Suddenly, boards begin covering the windows and doors; Audrey is up to a new trick. Mal attempts to undo the spell, but her magic is not strong enough now (the scepter's magic is growing stronger by feeding of Audrey's negative emotions). Uma joins hands with Mal and recites a counter-spell with her, removing the boards.
The boys arrive at the house, with Ben and Mal happily reunited. Seeing Uma, Ben tells her that he knew she could be part of the solution; Uma silently acknowledges Ben had been right back when they met. Carlos uses the chance to give Jane a necklace that has a combined version of their names on it. Jane becomes worried about her mother's lack of action to undo the spells. Doug and Gil offer to come with Jane to keep her safe, while Ben reveals he knows the location of fairy cottage. Jane arrives at the museum with Doug and Gil, finding her mother turned to stone. Unable to use the wand herself (lest risk another disaster like poking a hole in the barrier again), Jane sits nearby with Doug and Gil to keep her mother safe.
At fairy cottage, the VKs discover only a very shaken Chad, who promptly flees when he realizes Audrey is gone. As everyone leaves, Mal accidentally spills the beans about the plan to seal the barrier. An enraged Celia drops the ember in a bird bath, disabling its magic. Mal asks Uma to help her reignite the ember's magic, but she said “Bummer.” Uma and Harry leave to find Gil and return to the island, leaving Mal to try to explain things to her friends which doesn't prove to work. At that moment, Audrey turns Ben, Carlos, Jay, Evie and Dude to stone, leaving an upset Mal to reflect. Mal realizes that she deserves this isolation and loneliness for not having the courage to tell her friends the truth and try to find a way to resolve the barrier issue that wouldn't neglect the children of the isle. Mal races after Uma and Harry, catching them at Auradon Prep. Despite her pleas for forgiveness, Mal is told by Harry that Uma has made up her mind to return the island and abandon Auradon to Audrey's wrath. As they leave again, Mal reflects on her life since her arrival in Auradon, realizing that her "story" is not over yet, and that she can make it right. ("My Once Upon a Time")
Hearing Celia cry for help from the top of the school, Mal transforms into her dragon form, flying up to find Celia held captive by Audrey. Unable to breathe fire without risking Celia being injured, Mal is zapped by Audrey, hurting her wing. Hearing the commotion, Uma and Harry return. Seeing Mal refuse to breathe fire for Celia's safety, Uma realizes that Mal was genuine in her desire to make amends. As Mal lowers to the ground, Uma rushes up to her and tells Mal that she's there to help. Uma combines her magic with Mal's flames to restore the ember's magic. Mal fires a blast of magic from the ember, which clashes with one Audrey fires from the scepter; however, the ember overpowers the scepter, knocking Audrey out and returning her to normal. All the spells Audrey cast break. Audrey, however, has fallen into a coma due to the scepter's magic backfiring from the magic struggle. Mal tries using the ember to wake her, but cannot; she remembers Hades warning her that its full powers are unavailable to her.
The VKs and Ben take Audrey back to her room, wondering what they can do, as Audrey will slip away if not woken soon. Mal reveals Hades is her father, and that he will wake Audrey as a favor to her. Ben agrees to the plan, but he needs a team of guards to retrieve Hades as a precaution. Uma, Harry and Celia ask for a ride back to the island (along with picking up Gil), as they are needed there for the rest of the VKs. Mal agrees, telling Uma that she knows the island is in good hands with her. Hades is brought the next day, understandably confused by why "heroes" care so much for a "villain"; he flatly points out that Audrey's rampage is considered "an error in judgement", while people like him are locked way forever for attempting to do the same thing. Despite this, Hades uses his ember to wake Audrey, who is genuinely remorseful for letting her despair drive her to revenge. With his task done, Hades is escorted out; though Mal shares a moment with her father, glad for his help. He discretely gives the ember back to her, through a hug.
Sometime later, a celebration is held at the shore to honor Ben and Mal's engagement. Prompted by her friends to make a speech, Mal explains that it was thanks to Uma's pirates that Auradon was saved, and that it was her father Hades that saved Audrey; everyone has the capacity for both good and evil. She tells the people of Auradon that they cannot live in fear. It's time for forgiveness; the barrier around the isle of the lost must come down. Beast attempts to reason with Mal, only to be blocked by Ben, who explains that she's right; its time to move on from the past, to give the "villains" a chance at redemption. Ben declares the barrier will come down. Fairy Godmother gives Mal her wand, allowing her to bring down the barrier and restore the original bridge connecting the island to the mainland. The people of Auradon and the isle sing in joy about this new chance at redemption and harmony. The children of the isle, lead by Uma, Harry, Gil and Celia march on the bridge to Auradon, with a dragon puppet in honor of Mal. ("Break This Down") Lady Tremaine, Dr. Facilier and Mr. Smee also arrive in Auradon, happily welcomed by Dizzy, Celia, Squeaky and Squirmy. Harry asks if any of the other girls are taken and tried to kiss Uma, but she angrily walks away. Jay decides to take a gap year and explore Auradon with Gil, who suggests they visit jungles and icebergs. Jane tells Carlos that she's worried about meeting Cruella, only for Carlos to say the only thing they have to worry about is her reaction to Carlos wanting to be a vet. Hades arrives next, wondering if he's invited to Mal's wedding, making Ben understandably nervous; however, Hades wishes the couple happiness. Though when Mal's back is turned while hugging Ben, Hades gives a silent warning to his future son-in-law.
After the celebration, Mal, Evie, Jay and Carlos return to the bridge, wondering if their parents on the island miss them. Deciding to go for it, the four of them race to the bridge.
- Dove Cameron as Mal, daughter of Maleficent and Hades
- Sofia Carson as Evie, daughter of the Evil Queen
- Booboo Stewart as Jay, son of Jafar
- Cameron Boyce as Carlos De Vil, son of Cruella De Vil
- China Anne McClain as Uma, daughter of Ursula
- Mitchell Hope as King Ben, son of King Beast and Queen Belle
- Sarah Jeffery as Audrey, daughter of Aurora and Prince Phillip
- Thomas Doherty as Harry Hook, son of Captain Hook
- Dylan Playfair as Gil, son of Gaston
- Brenna D'Amico as Jane, daughter of Fairy Godmother
- Zachary Gibson as Doug, son of Dopey
- Jedidiah Goodacre as Chad Charming, son of Cinderella and Prince Charming
- Anna Cathcart as Dizzy Tremaine, daughter of Drizella Tremaine
- Jadah Marie as Celia Facilier, daughter of Dr. Facilier
- Jamal Sims as Dr. Facilier
- Christian Convery and Luke Roessler as Squeaky & Squirmy Smee, sons of Mr. Smee.
- Dan Payne as King Beast
- Keegan Connor Tracy as Queen Belle
- Judith Maxie as Queen Leah
- Melanie Paxson as Fairy Godmother
- Bobby Moynihan as Dude (voice only)
- Cheyenne Jackson as Hades
- Linda Ko as Lady Tremaine
- Faustino Di Bauda as Mr. Smee
- Good to Be Bad
- Did I Mention
- Queen of Mean
- Happy Birthday
- Do What You Gotta Do
- Night Falls
- One Kiss
- My Once Upon a Time
- Break This Down
- Dig a Little Deeper
- Descendants 3 began filming on May 22, 2018 ainVancouver and wrapped the production io July 16, 2018. Its working title is The Big Sleep.
- This is the fifth DCOM to receive a third installment, following Zenon: Z3, Halloweentown High, The Cheetah Girls: One World, and High School Musical 3: Senior Year (theatrical release).
- This was the last DCOM to be released in the 2010s decade.
- Dianne Doan (who plays Lonnie) is the only original cast member who does not reprise her role for this film.
- This was Cameron Boyce's last Disney role before his death.
- The film's premiere featured an opening and closing tribute to Cameron Boyce.
- The film was leaked online on July 26, 2019. Its source is unknown.
- As the film progressed, Audrey grew increasingly crazier/unhinged, likely due the scepter amplifying her jealousy towards Mal.
- Despite introducing Squeaky and Squirmy, along with Dizzy returning from the previous film, Celia is the only new VK to have a prominent role in the film.
- This film emphasizes that despite being labeled "villains", the residents of the Isle of the Lost have the capacity for goodness, just like "heroes" like Audrey can succumb to their negative emotions and become evil.
- A deleted scene had Celia giving Jane a prediction, about a handsome stranger she would encounter. Jane would later meet Harry Hook, who tries to woo her, only to be blocked by Carlos.
- Mal states nothing could undo the scepter's spells except Hades' ember, but its seems the magic of Fairy Godmother is also something they could have used. When Mal enters the barrier, her youth is restored, due to evil magic being neutralized by the barrier.
- The more Mal used the ember, the bluer her hair became; clear sign of her relying on her father's godly magic, instead of the fairy magic she inherited from Maleficent.
- When Audrey turns people to stone, Jane remains unaffected; possibly because at the time, she hasn't dried off from using the Enchanted Lake to avoid the sleeping spell.
- Jane kept a squirtwand full of the Enchanted Lake with her, just in case.
- ↑ "Lindsay B post". Twitter. Retrieved on February 17, 2018.
- ↑ "Production Weekly – Issue 1080 – THURSDAY, February 8, 2018 / 219 Listings – 44 Pages". Production Weekly. Retrieved on February 17, 2018.