BACKGROUND: Childhood bullying has long-term negative mental and physical health correlates, including weight gain and symptoms of depression. The purpose of this research is to examine whether bullying in the first year of school is associated with greater weight gain by early adolescence and whether adolescent depressive symptoms mediate this association. METHODS: Data were drawn from the Longitudinal Study of Australian Children. Children (N = 3929) were measured every 2 years; BMI and waist circumference were available from ages 4 to 15. Parents reported on bullying at age 6. Children reported on their depressive symptoms at ages 12-13. RESULTS: Participants who weighed in the obese category at age 4 had an over 50% increased risk of being bullied in school at age 6. Being bullied at age 6 was associated with excess weight gain between ages 6 and 15, defined as either BMI or waist circumference. Depressive symptoms at age 12 partially explained the association between bullying and increases in adiposity. None of the associations varied by gender. CONCLUSIONS: Similar to other forms of peer victimization, bullying early in school is associated with greater weight gain through early adolescence; depressive symptom is one mechanism that contributes to this association.