The Pumpkin King, Jack Skellington (Chris Sarandon](/actor/chris-sarandon) for speaking voice and Danny Elfman for singing), is a remarkably slender skeleton who has just finished another spooktacular Halloween. Despite the cheers and admiration from the residents of Halloweentown, he feels a deep sense of discontent and realizes that something crucial is absent from his life. Specifically, it could be the attention of Sally (Catherine O'Hara), a charmingly animated rag doll who harbors feelings for Jack, but he remains oblivious to her affections. Sally was fashioned by a sinister inventor in Halloweentown, the evil scientist (William Hickey), who keeps her imprisoned until she cleverly knocks him out by sneaking deadly nightshade into his soup.
One night, while reflecting on his feelings of emptiness in a graveyard—where he inadvertently disturbs Sally, busy gathering more deadly nightshade—Jack takes a stroll with his ghostly dog Zero. Their adventure leads them to an unusual circle of trees, each marked with a door that symbolizes a different holiday. Curiosity draws Jack to open the door marked for Christmas, and he is suddenly whisked away into Christmastown. Overwhelmed with wonder, Jack finds the sights and sounds enchanting and yearns to merge into this new celebration.
Returning to Halloweentown, Jack holds a town meeting to share his remarkable findings. His fellow townsfolk don't seem all that impressed, so he exaggerates the scarier elements of Christmas—such as the elusive Sandy Claws (Edward Ivory)—to capture their interest. However, his enthusiasm leads him to declare that they will take over Christmas. Jack starts assigning various tasks to his team: the evil scientist will create reindeer, and Halloweentown's mischievous trick-or-treaters are tasked with abducting Sandy Claws while Sally is commissioned to create Jack a Santa suit. Despite her warnings against such a disastrous plan, Jack's excitement blinds him to her concerns.
In the midst of their preparations, the trick-or-treaters return proudly with the Easter Bunny. Jack sends them back and eventually they return with Sandy Claws, who surprises Jack by having hands instead of claws. Jack instructs the trick-or-treaters to make Sandy Claws comfortable, but in a twist of fate, they hand him over to Oogie Boogie (Ken Page) instead.
Simultaneously, Sally successfully crafts a red suit (glaringly missing a hat, prompting Jack to take Sandy's) while the evil scientist's skeletal reindeer are harnessed to a sleigh filled with eerie toys. In a last-ditch effort to derail Jack's Christmas Eve plan, Sally attempts to sabotage him by adding fog juice to the town well, almost achieving her goal. But Zero, with his glowing nose, saves the day. Recognizing that only Sandy Claws can help Jack now, Sally bravely sneaks into Oogie Boogie's lair to rescue him.
As Jack launches into his Christmas Eve journey in the sleigh, he proves to be utterly clueless about the holiday spirit. His idea of a suitable gift for a child results in chaos, featuring items like a shrunken head and a malicious toy duck. This ultimately leads to pandemonium wherever he goes, and he is shot down from the sky by panicking townsfolk. Coming to terms with his blunder and affirming his commitment to being the best Pumpkin King possible, Jack races back to Halloweentown to locate Sandy Claws and restore the Christmas spirit.
In a climactic showdown, Jack confronts Oogie Boogie, liberates Sally and Sandy Claws, and brings Oogie's influence to an end. Santa Claus chastises Jack for trying to hijack another holiday and works his magic to save Christmas. As Jack and Sally return home, they witness the first snowfall brought by Santa, signifying a touch of magic in their lives. In a poignant moment amidst the snowflakes, Jack and Sally realize that their destinies are intertwined, and they were always meant to be together.
