Adolescent dropouts experience various psychosocial difficulties such as social stigma, depressive symptoms, and anxiety after they leave school. This study examined the longitudinal effects of social stigma on depressive symptoms, and the mediating effects of ego-resilience in the relationship between these two variables among South Korean adolescent dropouts aged 14 to 19. This study utilized four waves of data from the Out of School Panel Survey (N = 278), assessed annually from 2013 to 2017, which were analyzed using latent growth curve modeling. Both social stigma and depressive symptoms showed positive linear growth over time, while ego-resilience showed negative linear growth. The increase in social stigma was associated with an increase in depressive symptoms and a decrease in ego-resilience. Initial levels of ego-resilience mediated the relationship between the initial levels of social stigma and depressive symptoms. Moreover, changes in ego-resilience mediated the relationship between changes in social stigma and depressive symptoms. These findings highlight the need for tailored interventions and strategies for preventing depressive symptoms and building ego-resilience to help dropouts overcome social stigma. Copyright © 2020 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.