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.
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.
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.
A miserable conman and his partner pose as Santa and his Little Helper to rob department stores on Christmas Eve. But they run into problems when the conman befriends a troubled kid, and the security boss discovers the plot.
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.
Miser Ebenezer Scrooge is awakened on Christmas Eve by spirits who reveal to him his own miserable existence, what opportunities he wasted in his youth, his current cruelties, and the dire fate that awaits him if he does not change his ways. Scrooge is faced with his own story of growing bitterness and meanness, and must decide what his own future will hold: death or redemption.
In New York City for their annual tradition of Christmas Eve debauchery, three lifelong best friends set out to find the Holy Grail of Christmas parties since their yearly reunion might be coming to an end.