Random Wilder – The supposedly humble narrator of the story who is neither humble nor much of a narrator. He is mainly concerned with his own problems. Wilder is an aspiring writer who nurses a bitter rivalry with Ice Haven's current poet laureate, Ida Wentz. He lives alone and looks down on the general public.
Vida – Described as an "out-of-town guest", Vida is a struggling writer who is visiting her grandmother, Ida Wentz. She writes a magazine which doesn't sell. After reading some of Random Wilder's poems, she becomes obsessed with the neighbor who she describes as an "owlish oddity", and begins to follow him around.
David Goldberg – The silent boy who is kidnapped during the course of the story.
Charles – A quiet boy who only talks at length and intelligently to his young neighbor, George. He's disturbed by the behavior he observes from Carmichael, with whom he goes to school. Secretly, Charles is madly in love with his stepsister, Violet, and wishes to end the marriage of their parents in order for them to be together at a later date.
Carmichael – A "troubled youth." He speaks mainly to Charles, though the two are not exactly friends. After he loans Charles a book about the Leopold and Loeb murder (the contents of which are summarized in a one-page comic strip), Charles suspects he might be involved in David Goldberg's disappearance.
Violet – A teenager in her senior year of high school. She is romantically involved with a boy named Penrod and often daydreams about him. She is unhappy at home with her mother and stepfather, is teased at school, and appears to be friendly only with a girl named Julie.
Harry Naybors – A serious comic book enthusiast and critic. He is the first character to be introduced after David Goldberg. Harry is the only character to break the fourth wall and speak directly to the reader.
Mr. Ames – A private investigator who comes to Ice Haven to look into the disappearance of David Goldberg. He has angry outbursts but is otherwise emotionally unreadable. He cares deeply for both his wife and his work.
Mrs. Ames – Mr. Ames's wife, who is investigating the case alongside her husband. She grows increasingly fed up with him and their marriage. It is implied that she pursues multiple extramarital affairs while in Ice Haven.
Ida Wentz – Vida's kindly and emotional grandmother. A poet laureate residing in Ice Haven.
Julie Rathman – An overweight friend of Violet's who works at a stationery store and is generally miserable.
Kim Lee – A convenience store worker who is uncommunicative with customers.
Paula – A young girl who goes to school with Charles and Carmichael. She is taking ballet and is revealed to have a particularly gloomy outlook.
George – Charles's young neighbor in whom he confides. George rarely speaks and is never seen without his toy, Blue Bunny.
Blue Bunny – George's stuffed animal. In a short comic, Blue Bunny is shown in his anthropomorphic form, where he is revealed to be psychotic.
Penrod – Violet's love interest. He doesn't return Violet's affection at all.
Rocky – A caveman mainly concerned with survival, procreation, and other aspects of living in the year 100,000 B.C. He apparently was the first man to arrive at the location of modern-day Ice Haven.
Officer Kaufman – A police officer who appears on and off throughout the book.
