The study concerns the kinds of language styles in Inside Out cartoon movies. This study aims to analyze the types of language styles used and the dominant type used in the movie. The researcher used himself and the movie as an instrument. The research design is descriptive qualitative research. The analysis is based on the five language styles adopted from Martin Joos’ (1991) theory, they are frozen style, formal style, consultative style, casual style, and intimate style. The source of the data was taken from the Inside Out cartoon movie directed by Pete Docter. The researcher found that there are two hundred thirty data from the conversation in the movie performing the language styles. The collected data can be concluded that the type of language style that occurs dominantly in the movie is casual style. The two hundred and thirty cases consisted of formal (eleven cases), consultative (seventy-eight cases), casual (one hundred and thirty-one cases), intimate (ten cases), and frozen (none). That is, the casual style proved to be the most dominant used in this film for communication between family and close friends. Based on the research results, it is highly recommended that English Department students conduct further research on the five language styles used in other sources such as films, novels, or articles. This of course can be useful and can be used by teachers in the learning process of language styles, especially in the scope of learning English in the classroom for students. Key Words : Language Style, Inside Out, Movie