This study explored how social exclusion predicted adolescent wellbeing via stress, academic self-efficacy, and school satisfaction. Data were collected from 328 adolescents in Turkey. Mediation analyses revealed that the negative effects of social exclusion on wellbeing were partially mediated by stress, academic self-efficacy, and school satisfaction. Given its important role in students' social, academic, and psychological development, researchers and practitioners may need to give more attention to social exclusion as a key risk factor for decreased wellbeing.