Once upon a time, the Trolls thrived in a vibrant tree, embodying pure happiness through their songs, dances, and frequent hugs. Their joyful existence was shattered when they were found by the Bergens, gloomy creatures who could only experience happiness by consuming a Troll. Consequently, the Bergens held a yearly event known as "Trollstice," during which they feasted on Trolls, gaining happiness for a brief period.
On the day of Trollstice, young Prince Gristle (Christopher Mintz-Plasse) awakens his father, the king, voiced by John Cleese. As the Bergens gather around the Troll tree, Chef (Christine Baranski) prepares to serve up a Troll, specifically the joyous Princess Poppy (voiced by Iris Dohrn). Yet, to her dismay, Chef discovers that all the Trolls have vanished, replaced by wooden dolls with outlandish hair. In their successful escape, the Trolls retreat underground, leading the king to banish Chef from Bergen Town. Frustrated and seething, Chef vows to track down the Trolls and feast on them, while the king sadly shares with his son that nothing would ever bring him joy again.
Fast forward 20 years, the Trolls establish a new life in the forest under the leadership of Poppy (Anna Kendrick), who passionately leads her friends in song. With her father, King Peppy (voiced by Jeffrey Tambor), watching over them, Poppy’s eclectic group of Troll buddies includes Biggie (voiced by James Corden), a gentle giant with a tiny worm friend named Mr. Dinkles; Guy Diamond (voiced by Kunal Nayyar), who is known for his autotuned voice and ability to fart glitter; Cooper (voiced by Ron Funches), a Troll resembling a giraffe; fashion-forward twins Satin and Chenille (voiced by Aino Jawo and Caroline Hjelt); DJ Suki (voiced by Gwen Stefani); and the zen-like Creek (voiced by Russell Brand). Poppy plans a massive celebration to commemorate their new home. However, amidst this joy, Branch (Justin Timberlake) stands out as the only sour Troll, painted a dull grey and perpetually pessimistic. Secluded in his bunker to safeguard against the looming Bergen threat, Branch uninvitingly declines Poppy's spirited invitation.
The festivities commence, but the exuberant display of glitter, vibrant lights, and loud aural excitement soon attracts the attention of Chef, who now presents a disheveled appearance after two decades of relentless pursuit for the Trolls. As she barges into the forest, Chef starts capturing Trolls one by one, snatching Biggie, Creek, Cooper, Suki, Satin, Chenille, and the diminutive Smidge (voiced by Walt Dohrn). Meanwhile, the remaining Trolls cleverly conceal themselves in their forest surroundings.
Determined to save her friends, Poppy seeks help from Branch, but he remains uncooperative and reluctant. Undeterred, she then brings her fellow Trolls into Branch's shelter, much to his displeasure, as she resolves to rescue her friends on her own. As night falls, Poppy joyfully sings about keeping her spirits high, but an unfortunate encounter with a spider web lands her in trouble. Luckily, Branch intervenes just in time, warding off the spiders and inadvertently exposing them to a larger creature.
Ultimately, Branch decides to assist Poppy on her journey, albeit grudgingly. After resting for a while, the duo stumbles across a tunnel supposedly leading to Bergen Town. En route, they meet Cloud Guy (also voiced by Walt Dohrn), who offers to guide them through the perilous paths, one leading to Bergen Town and the other to doom. Branch's annoyance flares up as Cloud Guy attempts a high-five, causing him to break a stick in frustration. Poppy and Branch then find themselves in Bergen Town, absorbing the dreariness that envelops the lives of its citizens.
Seeking their friends, they navigate through the castle, following the glow from the Trolls' wristbands that signal the "hugging hour." Chef presents the captured Trolls to Gristle, now crowned king. She aims to revive Trollstice and pushes Creek forward as the first victim. Though initially hesitant, Gristle succumbs when Chef forcibly presents Creek to him, prompting his fellow Trolls to believe Creek has met his end. Chef then entrusts the remaining Trolls to Bridget (Zooey Deschanel), a sympathetic scullery maid, to await their fate.
While conversing with Bridget, the Trolls discover her unspoken affection for Gristle, igniting a plan to help her express her feelings. They inspire her with song, but Branch hesitates to join in, haunted by the past trauma of his grandmother's sacrifice during one of Chef's attacks. With Poppy’s encouragement, Branch ultimately chooses to help Bridget.
Bridget undergoes a striking transformation with the Trolls' help, adopting the persona of Lady Glitter Sparkles to catch Gristle’s attention during a date at a pizza place and skating rink. Despite initial awkwardness, Bridget gains confidence to confess her feelings, allowing a connection to blossom. The date takes a troubling turn when the Trolls realize Gristle possesses a jewel containing Creek. Chef unexpectedly interrupts, forcing Bridget to flee and inadvertently leaving behind a roller skate.
The Trolls plot to retrieve Creek from Gristle’s jewel but are captured by Chef, with Creek exposing his betrayal to save himself. This deeply affects Poppy, leading her to lose her vibrancy. In an act of vulnerability, Branch sings "True Colors," his heartfelt melody igniting his friends’ hope and restoring their color and happiness. Grateful for their friendship, Bridget assists the Trolls in their escape, appreciating how they guided her towards true happiness. Unwilling to abandon Bridget, Poppy rallies her friends to show the Bergens they can experience joy without devouring a Troll.
As the Bergens gather for a celebratory feast, Gristle initially hesitates for his date. Chef rushes them to begin without her, only to discover the Trolls have escaped. Mistaking Bridget for having eaten the Trolls, Chef orders her capture. In a surprising move, the Trolls burst into the gathering on Bridget's skateboards, asserting her as Gristle's intended date. Poppy enlightens Gristle on how he can experience happiness with Bridget, inspiring the other Bergens to recognize they too can be joyful without the grim need to consume Trolls.
With the rhythmic beat of "Can't Stop The Feeling," the feast transforms into a euphoric dance fest. In a final attempt to ensnare the Trolls, Chef finds herself thwarted as Bridget tosses a wooden spoon at her, sending Chef tumbling into chaos as the cart she rides rolls out of the castle, along with Creek.
Poppy ultimately receives the honor of being crowned queen of the Trolls, solidifying a new era where both Trolls and Bergens coexist harmoniously. Together with Branch, she embraces the future atop a towering tree. The movie closes with Chef and Creek, who, having landed atop an unsuspecting monster, find themselves in a comically perilous situation as they are engulfed whole.
