This research delves into the personality traits exhibited by the characters Ruth Jefferson and Turk Bauer in Jodi Picoult's novel Small Great Things (2016). Employing a psychology approach alongside McCrae and Costa's Five Factor Model theory, which consists of neuroticism, extraversion, openness to experience, agreeableness and conscientiousness. This research uses qualitative descriptive method. The data analyzed are words phrases, sentences, and paragraphs taken from the novel Small Great Things which represented personality traits on characters Ruth and Turk. The results of this research show that Ruth Jefferson has a high level of neuroticism, characterized by a tendency to experience negative emotions such as anxiety and sensitive. She also has traits of agreeableness which is forgiving, trusting, kind and sympathetic. Last, conscientiousness is ambitious show that Ruth is planful and hard working. Conversely, Turk Bauer has a high level of neuroticism, characterized by a tendency to experience negative emotions such as frustration and unstable. Turk also has traits of extraversion such as enthusiastic. He also has traits of agreeableness which is appreciative and loving. Last, conscientiousness is ambitious show that Turk is organized. This research provides a deeper insight of personality traits.