Shavira, Annisaa Rhaisa. 2023. Language Styles of Harry Potter’s Character in Harry Potter and The Prisoner of Azkaban Movie. Thesis. English Language Education Program, Faculty of Teacher Training and Education. Mulawarman University. Advisors: (1) Anjar Dwi Astuti, S.S, M.Hum., (2) Dr. Yuni Utami Asih, M.Pd. Knowing how to use proper words as well as understanding the relationship between language and culture involved are hardly achieved when the people engaged in the conversation do not understand the roles of languge style. This situation that leads this study to discuss the types of language styles and its affecting factors used by Harry Potter’s character in Harry Potter and The Prisoner of Azkaban movie. The theory applied in this study is language styles by Martin Joos (1967). Words, phrases, and sentences of Harry Potter’s conversations were the data in this study. They were collected from movie and movie script of Harry Potter and The Prisoner of Azkaban. The research design of this study was qualitative research. The results revealed four language styles and five affecting factors used by Harry Potter’s character in Harry Potter and The Prisoner of Azkaban movie. The four language styles were frozen, formal, consultative, and casual. As for the affecting factors, they were age, educational background, social class, profession, and culture of the participants. This study concludes each language style has its specific affecting factors due to the compatible relations between the two that complement the usage in daily conversation. This helps the users of language style to decide which language style be the most suitable for different types of conversation.