In a five-year longitudinal study, we investigated the role of body objectification in shaping girls' self-esteem and depressive symptoms over the course of adolescence. Multivariate Latent Growth Curve Modeling (MLGM) was used to test the association between body objectification and both self-esteem and depressive symptoms with data from 587 adolescent girls who began the study at age 13 and completed the study at age 18. Results revealed that body objectification decreased, self-esteem increased, and depressive symptoms remained relatively steady across adolescence. Girls who experienced decreases in body objectification also tended to increase in self-esteem and decrease in depressive symptoms over the course of adolescence, even after accounting for several factors known to be associated with positive youth development including race/ethnicity, socioeconomic status, educational achievement, religiosity, and body satisfaction. Practical implications for reducing objectification and enhancing girls' well-being through health, physical, and sexuality education, as well as through media literacy programs are discussed. Directions for future research are also discussed, including a greater focus on the role of race/ethnicity, research on boys, and the need for more experimental studies of body objectification. (Contains 4 tables, 1 figure and 1 note.)