George is a 28-year-old land surveyor and the owner of a third-generation family business. He seeks to provide an ideal, upper-middle-class home for his new wife and stepchildren. He views the heavily discounted Amityville property as a sign of success despite its grim history. As unexplained events plague the house, he becomes increasingly sleep-deprived, irritable, and disconnected from his work. He develops a severe obsession with the home's fireplace in order to combat a supernatural chill only he can feel.

Kathleen, a 30-year-old mother of three, is a devoted homemaker attempting to build a safe, happy environment for her newly blended family. She views the Amityville house as the foundation for their future and takes specific pride in her kitchen. Her domestic ideal shatters when she experiences deeply personal, invasive supernatural phenomena. These terrifying events transform her from a joyful mother into a highly cautious and fiercely protective survivor.

Father Mancuso is a Catholic priest with backgrounds in law and psychoanalysis who serves as a spiritual authority for the Lutz family. During his initial blessing of the house, a disembodied voice commands him to leave, initiating a series of distant supernatural attacks against him. He suffers from debilitating physical illnesses and unexplainable vehicular malfunctions. Furthermore, his rectory miles away from the property fills with a foul odor as he struggles to convince his bureaucratic superiors of the genuine demonic threat.

Jodie is an unseen entity residing in the Amityville house who presents itself to five-year-old Missy as a giant, friendly pig. Operating as an angelic figure to the child, the entity slowly reveals its demonic nature to the adults through terrifying physical manifestations. It leaves physical evidence of its presence in the snow and actively attempts to claim the house's youngest resident.

Daniel is Kathleen's nine-year-old son from a previous marriage. Initially a typical, well-behaved child, he begins acting out and fighting with his brother after moving into the Amityville house. He suffers a severe, physically impossible injury when a window inexplicably slams on his hand.

Christopher is Kathleen's seven-year-old son. Like his older brother, his normally calm demeanor vanishes upon moving into the new home. He becomes prone to sudden aggression and violent arguments, reflecting the corrupted atmosphere of the house.

Melissa, known affectionately as "Missy," is Kathleen's five-year-old daughter. Her innocence prevents her from recognizing the malevolence of the house, leaving her highly vulnerable to its influence. She forms a bond with a mysterious entity she believes to be a benign angel.

Ronald DeFeo Jr. is the former resident of the Amityville house who murdered his entire family a year before the Lutzes moved in. Although he is not physically present in the daily lives of the Lutz family, his legacy hangs heavily over the property. George Lutz discovers an unsettling physical resemblance to him and begins mimicking his erratic, isolated behaviors.

Harry is the Lutz family's Malamute dog. He acts as an early warning system for the property's malevolent energy, frequently exhibiting extreme lethargy and refusing to enter certain rooms. He demonstrates clear terror toward the basement and upper floors.

Joan is Kathleen's mother. She visits the Amityville property and immediately notices the pervasive, unnatural chill in the house and George's unkempt physical deterioration. She acts as a grounded, outside perspective on the family's rapid decline.

Jimmy is Kathleen's brother. He maintains a connection with the family during their isolation in the house. The house's malevolent energy directly impacts him when an envelope containing a large sum of cash inexplicably vanishes from his coat pocket during a visit.

Carey is Jimmy's wife and Kathleen's sister-in-law. During an overnight visit to 112 Ocean Avenue, she wakes at exactly 3:15 am and encounters the horrifying apparition of a sick young boy. Her experience forces George and Kathy to attempt a direct intervention against the entities.

Sergeant Gionfriddo is an Amityville police officer familiar with the property's gruesome history. He provides Father Mancuso with details about the DeFeo murders but becomes inexplicably nauseated while discussing the case. He leaves their meeting abruptly when the physical symptoms overcome him.

Francine is a young medium brought in by George to assess the supernatural activity. During her visit, she detects numerous spirits, confirms the house is built on a burial ground, and falls into a deep trance in the sewing room. The overwhelming demonic energy terrifies her, and she flees the property.

Eric is Francine's boyfriend who accompanies her to the Lutz home for the psychic investigation. He witnesses her terrifying trance firsthand and hastily evacuates the property alongside her when the energy becomes too dangerous.

Lou Zammataro is a police sergeant who responds to George's report regarding the torn garage door. While officially maintaining a skeptical, rational perspective as a law enforcement officer, he privately feels a deep, unnerving presence while standing on the property.

George Kekoris is an investigator from the Psychical Research Institute. He advises George Lutz on how to test the house's energy, specifically recommending that George observe the family dog's reactions to different rooms as a barometer for supernatural activity.

Father Ryan is a fellow priest who visits Father Mancuso during his severe illness. Representing the institutional skepticism of the Catholic Church, he suggests that Mancuso's ailments might be entirely psychosomatic and relays the Bishop's offer of psychiatric assistance.

Lorraine Warren is a clairvoyant and demonologist who participates in a seance at the abandoned house. She senses a threatening presence and definitively categorizes the force occupying the home as a demonic, non-human entity.

Ed Warren is a demonologist who investigates the property after the Lutz family's departure. He works alongside his wife and a news crew to determine the exact nature of the lingering entity inside the home.

Marvin Scott is a reporter who takes an interest in the supernatural claims surrounding the Lutz family. He coordinates a formal investigation of the empty house involving prominent psychic researchers and a news crew.

Aunt Theresa is Kathleen's aunt and a former nun. She senses immediate danger upon entering the Amityville property. She refuses to step foot in certain rooms and abruptly leaves after warning the family of the home's evil presence.

Bobby is a neighborhood boy who pays a brief visit to the Lutz family. Like Aunt Theresa, he becomes overwhelmed by the atmosphere inside 112 Ocean Avenue. He refuses to go upstairs and leaves the property quickly.

Louise DeFeo is a former resident of the Amityville house who was murdered in her bed. Though deceased, her trauma lingers on the property, manifesting in intensely personal dreams that disturb Kathleen's sleep.