Amid ethnic/racial stratification and oppression, parents' engagement in ethnic/racial socialization (ERS) practices foster resilience and positive outcomes in youth. Research has found inconsistent effects of ERS practices on adolescent academic outcomes and has neglected the intersectionality of race/ethnicity and gender. Using an intersectional approach and longitudinal design, we explored how N = 358 parents' ERS practices (cultural socialization, preparation for bias, and promotion of mistrust) predicted academic outcomes among male and female Black/African American, Asian American, Latinx, and White/European American high schoolers 1 year later. Ethnic/racial group differences in ERS practices were consistent across youth gender. Our intersectional approach revealed that cultural socialization predicted Asian American boys' academic achievement and that preparation for bias predicted Black/African American boys' academic achievement. Future studies should continue to explore the gendered construction of ERS messages and how they shape academic outcomes differently across diverse samples.