In the vibrant town of Santa Cecilia, Mexico, the story begins with Imelda Rivera, who once shared her life with a musician that abandoned her and their young daughter Coco to chase musical dreams. Heartbroken, she declared a ban on music within the family and founded a shoe-making business instead. Almost a century later, Miguel, her great-great-grandson and an aspiring musician, resides with Coco and their family. Despite openly defying his grandmother Elena's prohibition against music, Miguel yearns to emulate the legendary singer and actor Ernesto de la Cruz, a prominent figure from Coco’s past.
When Miguel accidentally damages a treasured photo of Coco with her parents on the family's ofrenda, he is shocked to discover a torn image of his great-great-grandfather holding Ernesto's famous guitar. Convinced that this means Ernesto is his ancestor, Miguel decides to seize the opportunity to showcase his talent at the upcoming Day of the Dead talent show. Ignoring his family's warnings, he sneaks into Ernesto's mausoleum, takes the guitar for his performance, only to find himself transformed into a ghost that no one can see, except for his loyal dog, Dante, and his skeletal relatives who journey from the Land of the Dead.
As Miguel travels through this enchanting yet perilous afterlife, he learns that removing Imelda’s photograph from the ofrenda cast a curse upon him. If he does not return to the living before sunrise, he risks becoming part of the dead forever. To break the curse, Miguel must obtain a blessing from a family member by using an Aztec marigold petal. Imelda offers him the blessing but makes it clear that he must forsake music when he returns. Miguel defiantly refuses and instead seeks Ernest's blessing.
During his adventure, Miguel crosses paths with Héctor, a spirited skeleton who once shared a musical bond with Ernesto. In exchange for Miguel's help in returning Héctor's photo to the living world, which he hopes will reconnect him with his long-lost daughter, Héctor agrees to assist Miguel in finding Ernesto. However, tensions arise when Miguel evades his relatives and infiltrates Ernesto's mansion, only to uncover the dark truth about his ancestor—a betrayal that saw Héctor poisoned by Ernesto, who subsequently appropriated his music for fame.
Trapped with Héctor in a cenote pit by Ernesto, Miguel soon realizes that Héctor is, in fact, his true great-great-grandfather, and that Coco is Héctor's daughter, the last living person who remembers him. With Dante's transformation into an alebrije, the dead Rivera family races against time to rescue them. Miguel uncovers the tragic truth: Héctor's return home for Coco led to his demise. Ultimately, a heartfelt reunion unfolds, allowing Imelda and Héctor to reconcile their past.
As they storm Ernesto's concert at dawn, they work together to unveil Ernesto's treachery. Ernesto faces his fate when a church bell falls upon him—irony not lost on those who remember the past. As dawn breaks, the threat of oblivion looms over Héctor, who is on the brink of being forgotten by Coco. In an act of unconditional love, Imelda grants Miguel her blessing without strings attached, permitting him to return to the living.
Back in the living world, Miguel serenades Coco with a heartfelt song written by Héctor, rekindling her memories of him. With newfound clarity and connection, Coco presents Miguel with a torn photograph that reveals Héctor's face. The family reconciles and embraces music once more.
One year later, Miguel proudly displays the family ofrenda—now adorned with photographs of Coco and Hector, alongside a note exposing Ernesto's deceit. With the community now honoring Héctor, he and Imelda joyfully reunite with Coco in the Land of the Dead, where they are embraced by Miguel's enchanting melodies, bridging both the living and the departed.
