Objectives: The overall aim of the study was to investigate the applicability of Objectification Theory to the mental health of early adolescent girls, in particular, their dieting behaviors and depressive symptoms. Both predictors and consequences of self-objectification were examined. Methods: A sample of 204 girls with a mean age of 11.6 years completed questionnaire measures of media consumption, time spent on sports and hobbies, appearance conversations, self-objectification, body shame, dieting, and depressive symptoms. Results: Structural equation modeling showed that magazine and Internet exposure and appearance conversations with friends predicted self-objectification. Self-objectification itself predicted body shame, which in turn predicted both dieting and depressive symptoms, in accord with the pathways postulated by Objectification Theory. Conclusions: The results confirm that, as is the case with adult women, self-objectification plays a significant role in the mental health of early adolescent girls.