When Jesper distinguishes himself as the Postal Academy's worst student, he is sent to Smeerensburg, a small village located on an icy island above the Arctic Circle, where grumpy inhabitants barely exchange words, let alone letters. Jesper is about to give up and abandon his duty as a postman when he meets local teacher Alva and Klaus, a mysterious carpenter who lives alone in a cabin full of handmade toys.
Inside a snowflake exists the magical land of Whoville. In Whoville, live the Whos, an almost mutated sort of Munchkin-like people. All the Whos love Christmas, yet just outside of their beloved Whoville lives the Grinch. The Grinch is a nasty creature that hates Christmas, and plots to steal it away from the Whos, whom he equally abhors. Yet a small child, Cindy Lou Who, decides to try befriending the Grinch.
Tired of scaring humans every October 31 with the same old bag of tricks, Jack Skellington, the spindly king of Halloween Town, kidnaps Santa Claus and plans to deliver shrunken heads and other ghoulish gifts to children on Christmas morning. But as Christmas approaches, Jack's rag-doll girlfriend, Sally, tries to foil his misguided plans.