Background: Despite school-based and other interventions for pediatric obesity, many obese youth of the present generation will persist in their obesity into adolescence and adulthood. Thus, understanding not only how better to tailor weight interventions but how to promote overall adjustment for persistently obese youth is of utmost importance. This study examined the role of perceived social support in predicting later psychosocial status (ie, weight-related quality of life) for persistently obese adolescents. Methods: This study used a longitudinal design whereby persistently obese and nonoverweight comparison youth completed measures at 2 time points approximately 4 years apart. Results: Obese youth reported lower levels of social support than comparison youth. Among obese youth, classmate and teacher support predicted future weight-related quality of life. Conclusions: Social support, particularly from classmates, is an important predictor for the longitudinal psychosocial functioning of persistently obese youth. High levels of perceived teacher support may signal the presence of other psychosocial difficulties. Implications for school-based interventions are discussed.