The McCallister family is preparing to spend Christmas in Paris, gathering at Peter and Kate's home in a Chicago suburb the night before their departure. Their youngest son, Kevin, is the subject of ridicule by his older siblings because of his immaturity. During a scuffle with his oldest brother Buzz, Kevin accidentally ruins the family dinner; while cleaning up the mess, Peter inadvertently throws away Kevin's flight ticket. As punishment, Kate sends Kevin to the attic, where he angrily berates his mother and wishes his family would disappear. During the night, heavy winds cause a power outage that resets the alarm clocks and leads the family to oversleep. The next morning, in the chaotic rush to leave for the airport, Kevin is accidentally left behind.
Kevin wakes to find the house empty and, thinking that his wish has come true, initially enjoys his newfound freedom. He ransacks Buzz's room, buys and eats whatever he wants, and watches violent movies. However, Kevin soon becomes frightened by his next door neighbor, Old Man Marley, who is rumored by Buzz to be a serial killer who murdered his own family in the 1950's, as well as the "Wet Bandits", Harry and Marv, a pair of burglars who have been breaking into other vacant houses in the neighborhood and have targeted the McCallisters' house. Kevin tricks them into thinking that his family is still home, forcing them to put their plans on hold.
Kate realizes mid-flight that Kevin was left behind. Upon arrival in Paris, the family discovers that all flights for the next two days are fully booked. While the rest of the family stay in Peter's brother's apartment, Kate manages to get a flight to the United States, but it is a flight to Dallas, Texas.
On Christmas Eve, Kate ends up in Scranton, Pennsylvania, where all flights to Chicago are fully booked. She ends up riding with a polka band who are driving to Milwaukee and whose leader, Gus Polinski, offered to let her ride with them to Chicago after overhearing her desperation to get home. Meanwhile, Harry and Marv finally realize that Kevin is home alone, and Kevin overhears them discussing plans to break into his house. Kevin starts to miss his family and asks the local Santa Claus impersonator if he could bring them back for Christmas. He goes to a church and watches a choir perform, then meets Old Man Marley, who dispels the rumors about him. He points out his granddaughter in the choir, whom he is unable to spend Christmas with, as he and his son are estranged; Kevin suggests that he should reconcile with his son.
Kevin returns home and rigs the house with booby traps to take on the burglars. Harry and Marv break in, spring the traps, and suffer various injuries. While the duo pursues Kevin around the house, he calls the police and flees, then lures Harry and Marv into a neighboring home which they previously broke into. They catch him and prepare to get their revenge, but Marley, who is next door checking on his son's house, intervenes and knocks them unconscious with his snow shovel. The police arrive and arrest Harry and Marv, having identified all the houses that they broke into due to Marv's destructive characteristic of flooding them.
On Christmas morning, Kevin is disappointed to find that his family is still gone. He then hears Kate enter the house and call for him; they reconcile and are soon joined by Peter, Buzz, Jeff, Megan, and Linnie, who managed to return by catching a flight to Dallas and then a connecting flight to Chicago. Kevin keeps silent about his encounter with Harry and Marv, although Peter finds Harry's knocked-out gold tooth. Kevin then observes Marley reuniting with his son, daughter-in-law, and granddaughter. Marley notices Kevin, and the pair wave to each other knowingly. The film ends with Kevin getting into trouble when Buzz discovers the mess in his room which Kevin went into earlier.
Writer and producer John Hughes conceived Home Alone while preparing to go on vacation. He said: "I was going away on vacation, and making a list of everything I didn't want to forget. I thought, 'Well, I'd better not forget my kids.' Then I thought, 'What if I left my 10-year-old son at home? What would he do?'" Hughes wrote eight pages of notes that developed into the screenplay. Imagining that children are naturally most scared of robbers, Hughes also worked that aspect into the plot of the film.
Home Alone was initially set to be financed and distributed by Warner Bros.
Reception
Home Alone grossed $285.8 million in the United States and Canada and $190.9 million in other countries for a worldwide total of $476.7 million, against a production budget of $18 million. In its opening weekend, Home Alone grossed $17 million from 1,202 theaters, averaging $14,211 per site and just 6% of the final total and added screens over the next six weeks, with a peak screen count of 2,174 during its eighth weekend at the start of January 1991.
