This study examined the extent to which parental and peer support influenced youth's depressive symptoms during emerging adulthood directly and indirectly through perceived social stigma, using the longitudinal survey on school dropout youth conducted by the National Youth Policy Institute. The present study included 776 adolescents (boys n = 444). The results indicated that parental and peer support in the beginning of school dropout (age 17) negatively affected the youth's perceived social stigma 2 years later (age 19). Their perceived social stigma was significantly and positively associated with depressive symptoms in emerging adulthood (3-4 years after school dropout, age 21). Second, depressive symptoms were not directly influenced by parental and peer support during the early years of school dropout but were significantly reduced through reduced social stigma. Results from the present study are expected to inform efforts for developing preventive intervention programs to support healthy adjustment among school dropouts in Korea.