Guided by a social ecological perspective, the aim of this study was to investigate the predictive strength of individual (barrier self-efficacy), social environmental (support from parents, friends, physical education teachers), and physical environmental variables (equipment accessibility, neighborhood safety) toward physical activity among school students. Participants were 285 students enrolled in a suburban public school. Hierarchical linear regression analysis highlighted the influence of self-efficacy, social support from parents, friends, physical education teachers, and accessible equipment on students' physical activity. The findings indicated that physical educators and health promoters need to consider multiple factors as they design effective interventions to promote physical activity and prevent physical inactivity among school students. This study also supported the use of a social ecological perspective to investigate students' physical activity.