We examine the pathway of internalized stigma between weight bias (perceived stigma) and mental health in adolescents. We used a sample of 457 junior high school students for data analysis. Based on the mediation analysis, self-esteem is a more prominent mediator than internalized stigma in the pathway from perceived weight stigma to mental health in our sample. Adolescents who perceived themselves to be obese or overweight were more likely to exhibit the association between perceived stigma and depression, compared to those who perceived themselves as normal or underweight. Health practitioners, teachers and parents should pay extra attention to adolescents who perceived themselves as obese or overweight and provide means to improve their self-esteem.