Objectives: Life satisfaction among Korean youths is the lowest among OECD countries, and the rate of perceived stress, depression, and suicidal thoughts have been increasing steadily since 2015. The general framework for the discussion of mental health problems has been psychological rather than sociological. The purpose of this study is to understand adolescent mental health from a social perspective by examining the effect of perceived socioeconomic status on depression, and examine the mediating role of social withdrawal in the relationship. Methods: The study sample included 1,671 adolescents from the 7th wave of the Korea Child and Youth Panel Survey (KCYPS). The main variables investigated were perceived socioeconomic status, social withdrawal, and depression. Results: Results showed that the lower the perceived socioeconomic status, the higher the level of depression. Lower perceived socioeconomic status increased the level of social withdrawal, and the social withdrawal was found to have a partial mediating effect on the relationship between socioeconomic status and depression. Conclusions: Findings indicates that the perceived socioeconomic status that reflects social rank and relative deprivation has influence on adolescents’ social withdrawal and depression. The study speaks to the importance of social determinants of mental health, and has implications for changing the environment in order to improve the mental health of adolescents.