This study explored the factor structure and psychometric properties of the Perceived Sense of School Membership (PSSM-18) Scale in two samples of South African adolescents. Principal components analysis (n = 1,052; males = 50.86%, M_age = 14.89, SD = 1.68) supported the retention of 15 items across a revised, three-factor structure of acceptance, belonging, and inclusion (PSSM–South African version [PSSM-SA]). Confirmatory factor analysis (n = 1,418; males = 49.86%, M_age = 14.93, SD = 1.70) provided an acceptable level of fit for the PSSM-SA. The structure was found to be invariant across sex, age, and poverty quintile groupings. Follow-up group comparisons showed selected scales were able to discriminate between groups and predicted alcohol and substance use, and the mean inter-item correlations indicated each scale possessed an appropriate level of internal consistency. The findings suggest the PSSM-SA is a valid and reliable measure of school belonging among South African high school–age children.