Sarah is a stubborn young girl who frequently clashes with her emotionally distant mother, Martha. She feels alienated from her immediate family's severe dynamic and strongly prefers the warmth of her extended relatives, especially her aunt and her cousin Margaret. Writing as an elderly widow decades later, she records her early childhood memories during the escalating paranoia in Massachusetts. She struggles to understand adult hypocrisy and the strict rules governing her community.

Martha is an outspoken woman in her forties who refuses to conform to the docile behavior expected of Puritan wives. She cares deeply for her family but rarely displays outward affection, leading to ongoing tension with her daughter Sarah. She maintains a secret family history in a red book and frequently clashes with neighbors over property lines, straying livestock, and matters of principle.

Thomas is a seven-foot-tall Welsh immigrant whose massive physical size and status as an outsider make him an object of intense suspicion in Massachusetts. He possesses a mysterious military past in England that he prefers to keep hidden from his children. He serves as a stoic provider for his family while absorbing the prejudices of the Puritan authorities.

Mercy is an orphaned teenager who was abducted by Indigenous raiders and held captive for three years before the Carriers ransom her to help with heavy farm work. Her face bears visible smallpox scars, and she possesses a sly, manipulative temperament. She repeatedly causes trouble within the household through theft, false claims, and physical intimidation.

Margaret is an eleven-year-old girl who forms an immediate, strong attachment with her younger cousin Sarah. She possesses a highly imaginative perspective, frequently speaking to invisible beings that others cannot see. She acts as an emotional anchor for Sarah during a period of intense family upheaval.

Roger is Sarah's charismatic uncle who considers himself a surgeon and an expert in detecting witches. He easily charms his young niece with magic tricks and tales of military battles, but his outward charm masks a heavy drinking habit and an obsession with claiming the Allen family farm for himself.

Mary is Martha's younger sister, known for her gentle and nurturing disposition. She provides the maternal warmth that Sarah desperately craves, making the Toothaker farm a temporary haven for the young girl. She tends to be overly passive, rarely interfering with her husband's questionable habits or mounting grudges.

Allen is Roger and Mary's eldest son, who inherits his father's deep-seated resentment toward the Carrier family. He firmly believes the Allen homestead belongs to his family and frequently threatens to take the property by force.

Tom is Sarah's slightly older brother and her closest companion among her siblings. He possesses an empathetic and sensitive nature, which often makes Sarah feel overly protective of him. Despite his quiet demeanor, he proves capable of quick thinking during emergencies on the farm.

Richard is the eldest Carrier son, entering his late teens as the family settles in Andover. He is quiet, brooding, and keeps mostly to himself, but he remains fiercely loyal to his parents and siblings. His stoic nature draws the unwanted attention of the hired girl, Mercy Williams.

Andrew is the middle Carrier son whose early contraction of smallpox forces the entire family into quarantine. The illness leaves him physically weakened and mentally impaired, though he remains a core part of the family's daily survival efforts.

Hannah is the youngest Carrier child, only one year old when the story begins. Her early life consists of constant disruption, being shuttled between households in the harsh winter to avoid disease. She requires constant care from her older siblings and relatives.

Doctor Ames is a young physician with ties to the Carrier family. He possesses knowledge about Thomas Carrier's mysterious history in England and holds key information regarding the private affairs of the local families during the rising hysteria.

Grandmother Allen is a prosperous and respected widow who takes in her daughter Martha's family when they flee an epidemic. She manages the strict rules of the Puritan community, advising her strong-willed daughter to maintain a pious exterior to avoid drawing the suspicion of local church leaders.

Reverend Dane is a semi-retired preacher in the Andover community who exhibits a gentler interpretation of Puritan faith compared to his peers. He frequently uses his influence to protect vulnerable families from the harsh judgments of local authorities.

Reverend Barnard is a strict, rigid minister who uses fear of God and the devil to control his congregation. His sermons heavily emphasize sin and divine retribution, stoking the anxieties of a community already dealing with disease and isolation.

Robert Russell is a neighboring farmer who occasionally assists the Carriers with their crops. He acts as a messenger of local news and gossip, keeping the isolated family informed about the rising tensions and accusations spreading through the nearby settlements.