Sam Baldwin is a widower with an 8-year-old son named Jonah. After losing his wife to cancer, Sam decides to move with Jonah from his home in Chicago to a houseboat community in Seattle to start over. Sam doesn't think about replacing his wife, but Jonah knows that his dad is depressed and needs a new wife. He takes matters into his own hands on Christmas Eve and calls a radio show, where he explains the situation to the sympathetic host. Womens' response to the show is so huge that it catches the attention of Annie Reed, an engaged headline-writer in New York. As she researches the story, she feels drawn to Sam and ends up writing him a letter that Jonah selects as "the one" from the thousands of letters resulting from the show. Sam and Annie live across the country from each other. All the odds are against them meeting and falling in love, but 8-year-old Jonah somehow knows that they are destined to be together. After a wild adventure, destiny steps in and takes its course.