Clark Griswold, a well-intentioned but often bumbling everyman, sets out to create the perfect Christmas for his family. Full of holiday spirit, he becomes obsessed with ensuring everything goes according to his idealistic plan, from covering his house in a blinding number of Christmas lights to insisting on finding the largest and most beautiful Christmas tree in the forest. His wife Ellen, teenage daughter Audrey, and pre-adolescent son Rusty are both amused and resigned to their father's Christmas craziness.

As the big day approaches, a series of guests arrive at the Griswold residence, including Ellen's parents, Clark's parents, his wacky Uncle Lewis and Aunt Bethany, and his redneck cousin Eddie with his family in tow. The house becomes a cramped and chaotic hub of quirky personalities and clashing agendas. Clark's attempts to provide a traditional Christmas experience are met with one comical disaster after another, testing his patience and sanity. With each new challenge, the prospect of a peaceful holiday seems increasingly out of reach.