Past research suggests that polygenic scores for major depressive disorder (MDD-PGS), family conflict, and parental acceptance may all predict depressive outcomes among adolescents. Few studies have examined the interplay of these factors through gene–environment interaction (GxE) and gene–environment correlation (rGE) in racially/ethnically diverse samples of adolescents. Methods: Utilizing latent curve analysis and growth mixture modeling in a diverse sample of 10,771 adolescents from the Adolescent Brain and Cognitive Development (ABCD) study, the present study examined how MDD-PGS, family conflict, and parental acceptance predicted depressive trajectory class membership through GxE and rGE in independent models for Black, Latinx, and White adolescents. Results: Among all youth, MDD-PGS and family conflict were associated with greater intercept-levels of depressive symptoms. Among Latinx and White youth, parental acceptance was associated with lower intercept levels of depressive symptoms. MDD-PGS (among all youth), lower parental acceptance (among Latinx and White youth), and greater family conflict (among White youth) increased odds of higher-risk trajectories. Evidence of rGE through family conflict was found among White youth. No evidence of GxE was found. Conclusion: Our findings highlight utility of MDD-PGS and the need to expand conceptualizations of environment to identify salient supportive and stressful experiences across racially/ethnically diverse youth.