Individuals’ well-being underpins a strong and sustainable society. Schools are increasingly recognized as key facilitators of well-being producing young people who can flourish across the life span. The current research explores and extends a new model that integrates core aspects of school relational climate (teacher and peer relationships) and school identification (connectedness, belonging) in explaining student negative well-being (depression and stress) in a non-Western cultural context. Measures included students’ perceptions of school relational climate, school identification, stress, and depressive symptoms in 1369 students across six Chinese schools. The results indicated that school relational climate and school identification were significantly associated with Chinese adolescents’ negative well-being in line with predictions based on the social identity perspective; there was also evidence that school identification mediated school-based relationships and negative well-being. The findings provide greater confidence in the variables of school relational climate and school identification in being related to youth well-being and showcase their generalizability and applicability to non-Western cultural settings. The research also provides insights into pathways forward to address mental health in Chinese schools through school relational climate.