This study aimed to assess the involvement of non-Catholic students in the Catholic school environment. Adopting a quantitative approach, descriptive design, and survey method, the study was conducted at Saint Paul University Surigao with 106 selected non-Catholic senior high school students. The findings revealed that most of the participants were female, with Grade 12 students being the majority. Regarding religious affiliation, the largest group belonged to the United Church of Christ in the Philippines (UUCP). The involvement of non-Catholic students in the school environment was highest in the social and pedagogical aspects, followed by spiritual engagement. No significant difference in involvement was found based on sex, religious affiliation, or academic strand. However, psychological involvement differed significantly between Grade 11 and Grade 12 students, with Grade 12 students reporting higher levels of psychological support. The study emphasizes the need for inclusive practices in curriculum development and enhancing support for non-Catholic students in psychological and spiritual areas.