This study examined the unique longitudinal effects linking academic competence, social competence, and internalizing symptoms from childhood to adulthood. A multimethod and multi-informant approach was used to assess psychopathology and competence in 205 participants during four developmental periods. Social competence in childhood had a cascading effect on internalizing symptoms in adolescence, whereas social and academic competence in emerging adulthood had dual cascading effects on internalizing in young adulthood. Results suggested a developmental cascade beginning with externalizing symptoms in childhood, which contributed to lower academic achievement in adolescence, which in turn influenced social competence in emerging adulthood and internalizing symptoms in young adulthood.