The Amityville Horror is the title of a book written by Jay Anson that recounts the supposedly true story of the Lutz family after they moved into 112 Ocean Avenue in Amityville, New York. The book chronicles the paranormal encounters the Lutzes claim to have had in the short time they lived in the house, and much controversy has swirled around the validity of the accounts and the accuracy of the re-telling. While the disputed elements of the Lutz tale of the Amityville Horror remain in question, the house on Ocean Avenue was, in fact, the site of the brutal murder of the Defeo family.

The Lutz family moved into the house in December of 1975 with the knowledge that Ronald Defeo Jr. had shot and killed six members of his family in the house a year prior. George and Kathleen Lutz decided this would not be an issue for them and they moved into the house with their children; the family stayed there less than thirty days. The Amityville Horror had begun and each family member began to experience their own personal paranormal happenings.

The first paranormal occurrence considered to be a part of the Amityville Horror occurred when the Lutz family had a priest come bless the house at the behest of one of George Lutz’s friend. Upon spreading holy water and praying, the priest claimed to hear a man’s voice gruffly protest and tell him to “Get out.” He did, and advised George Lutz to keep his family out of that particular room in the house.

Other paranormal activities persisted and the Amityville Horror became more intense. Kathleen Lutz began having nightmares about the Defeo murders; George Lutz woke up every night around three in the morning, just around the time the Defeo murders had taken place; Missy Lutz developed an imaginary friend with the shape of a pig and demonic, red eyes; the walls leaked green slime; and strange noises could be heard throughout the house.

After the Lutz family moved out of the Amityville Horror house, other residents moved in and none have complained of any paranormal activity. Much of the Lutz family’s story has been disputed throughout the decades following the Amityville Horror, and many critics claimed George and Kathleen Lutz outright lied about their experiences in the house. While the book was based on supposed actual events, its marketing called it a "true story," thereby lending validity to all aspects of the book. George Lutz later said the book was mostly true.

Several films have been made about the Amityville Horror and the story remains a staple in pop culture, despite its still-swirling controversy. The house on Ocean Avenue has been modified, as has its address, to deter tourists from seeking out the private residence.