Kono, S. R. (2024). Emily’s Personality Changes in Case 39 by Ray Wright. Undergraduate Thesis. English Language Education Study Program. Faculty of Letters and Culture. Universitas Negeri Gorontalo. Principal Supervisor : Novi Rusnarty Usu, S.Pd, M.A, Co-supervisor: Farid Muhamad, S.Pd, M.A This study examines the behavioral changes of Emily, the main character in the film script Case 39. According to Taufiqurrahman (2018), personality encompasses the activities of an organism, implying it is intrinsic to human behavior. To analyze Emily's behavioral shifts, the research employs Sigmund Freud's psychoanalytic theory, specifically the Structure of Human Psyche (id, ego, superego) as outlined by Boeree (2006; 4). Freud is recognized as the pioneer of psychoanalysis. The study uses a qualitative descriptive method and a psychoanalytic approach. Various data collection methods were utilized for this research. The findings identify several stages in the transformation of Emily's behavior. Ultimately, the study concludes that incidents affecting Emily led to changes in her personality, impacting her psychological health, as evidenced by alterations in her id, ego, and superego. Keywords : Personality Changes, Psychoanalytic, Structure of Human Psyche (id, ego, superego).