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.
Scott Calvin is an ordinary man, who accidentally causes Santa Claus to fall from his roof on Christmas Eve and is knocked unconscious. When he and his young son finish Santa's trip and deliveries, they go to the North Pole, where Scott learns he must become the new Santa and convince those he loves that he is indeed, Father Christmas.
Caroline and Lloyd are a married couple constantly at each other's throats, masters at crafting acid-tongued barbs at the other's expense. Indeed, they are so obsessed with belittling each other that they never stop -- not even at gunpoint. The gunman is Gus, a thief on the run from the police, who kidnaps the couple as an insurance policy, planning to use their home as a hideout. But their incessant bickering proves more than Gus bargained for, forcing him -- for the sake of his own sanity -- into the unenviable role of peacemaker. To make things even worse for Gus, he discovers that he has taken the couple hostage the night of their big Christmas party, and the guests are already on the way. Not wanting to leave Lloyd and Caroline unattended, Gus opts to attend the party, pretending to be the couple's marriage counselor. This naturally leads to a series of comic confusions, as the hostage crisis and marital tensions head towards their inevitable conclusion.
Meet Howard Langston, a salesman for a mattress company is constantly busy at his job, and he also constantly disappoints his son, after he misses his son's karate exposition, his son tells Howard that he wants for Christmas is an action figure of his son's television hero, he tries hard to to make it up to him. Unfortunately for Howard, it is Christmas Eve, and every store is sold out of Turbo Man, now Howard must travel all over town and compete with everybody else to find a Turbo Man action figure.
Better watch out! The big guy in red is coming to town once again. This time, Scott Calvin -- also known as Santa Claus -- finds out there's an obscure clause in his contract requiring him to take on a wife. He has to leave the North Pole to fulfill his obligations, or else he'll be forced to give up his Yuletide gig.
Fred Claus and Santa Claus have been estranged brothers for many years. Now Fred must reconcile his differences with his brother whom he believes overshadows him. When an efficiency expert assesses the workings at the North Pole and threatens to shut Santa down, Fred must help his brother to save Christmas.
6-year-old Susan Walker has doubts about childhood's most enduring miracle—Santa Claus. Her mother told her the 'secret' about Santa a long time ago, but, after meeting a special department store Santa who's convinced he's the real thing, Susan is given the most precious gift of all—something to believe in.
Luther Krank is fed up with the commerciality of Christmas; he decides to skip the holiday and go on a vacation with his wife instead. But when his daughter decides at the last minute to come home, he must put together a holiday celebration.