The governess is naive, deeply caring and attentive, if somewhat self-centered. She grew up in poverty, and she's easily impressed by the good manners and wealthy lifestyle of the children and their uncle. As she begins to see ghosts at Bly, the governess grows increasingly concerned, protective of the children, and unsure of the nature of her reality. She believes herself to be fighting evil spirits for young children's souls. She also has feelings for the children's uncle, which cloud her judgment. Her words and actions grow increasingly desperate and urgent toward the end of the novella. She may be an unreliable narrator, giving the reader an inaccurate version of events.
Miles appears charming, polite, and attractive at first. He's a bright student with a big imagination, and he's unusually well-behaved. Later in the story Miles proves himself to be intelligent and calculating. Still polite on the surface, Miles begins to show the governess he can be "bad" if he chooses. He expresses a desire to be independent of the women at Bly, since he's growing into a young man. The governess believes Miles to be possessed by the spirit of Peter Quint.
Flora appears to be an innocent and imaginative child. Her angelic appearance—blond hair and blue eyes—and her shy, welcoming manner enchant the governess. Flora proves more independent and aware than she seems at first. Flora works with Miles to trick the governess, and, later, wanders outside on her own. The governess believes Flora to be possessed by the spirit of Miss Jessel.
Mrs. Grose is hardworking, practical, and kind. The governess describes her as a "stout simple plain clean wholesome woman." She has less education than the governess and is illiterate. Mrs. Grose respects and trusts the governess as her superior but also wants to do what's best for the children, putting her in difficult situations when she and the governess disagree. She is unable to see the ghosts and is skeptical about their existence until the end of the novella.
Peter Quint is the first ghost to appear to the governess, and possibly the ghost who first appears to Miles. The governess describes him as handsome, like an actor. But both she and Mrs. Grose (who knew Quint) agree he is "never a gentleman"—implying he has been guilty of wrongdoing. Mrs. Grose also describes him as being "too free," particularly in his relationship with Miles. As a servant he was in a lower social class than the children. Quint died after slipping and falling on an icy road in the winter before the story takes place. He had been leaving the public house, or pub, and was intoxicated.
Miss Jessel is the more tragic of the two ghosts. She was young when she worked at Bly; Mrs. Grose indicates the children's uncle tends to hire young, attractive women. As a teacher she had a high social standing, and her affair with Peter Quint compromised her career. Mrs. Grose's account of the scandal implies Miss Jessel became pregnant with Quint's child and committed suicide. She reappears wearing black, a color of mourning.