Historic racial disparities in the United States have created an urgent need for evidence-based strategies promoting African American students' academic performance via school-based ethnic-racial socialization and identity development. However, the temporal order among socialization, identity, and academic performance remains unclear in extant literature. This longitudinal study examined whether school cultural socialization predicted 961 African American adolescents' grade point averages through their ethnic-racial identities (49.6% males; M[subscript age] = 13.60; 91.9% qualified for free lunch). Results revealed that youth who perceived more school cultural socialization had better grades 1 and 2 years later. In addition, identity commitment (but not exploration) fully mediated these relations. Implications for how educators can help adolescents of color succeed in schools are discussed.