INTRODUCTION: Extensive evidence demonstrates that early life adversity (ELA) has enduring contributions to psychological and physical problems, yet little research has examined how ELA may potentially influence positive adaptation. In this longitudinal, multi-method study, we explored prospective relations from childhood ELA subtypes (i.e., relational, environmental, biological) to adolescents' observed prosocial behavior (i.e., resource allocation to benefit others) via parent reports of childhood cognitive and affective empathy. METHODS: Participants were 250 youth (50% assigned female at birth; 46% Latine, 18% Black, 11.2% White, 0.4% Asian, and 24.4% multiracial) and parents who completed laboratory assessments at ages 4, 8, or 17. ELA across the first 4 years of life and childhood empathy (age 8) were assessed via parent reports, whereas prosocial behavior was measured using teacher reports (age 8) and a computer-based behavioral assessment (age 17). RESULTS: Controlling for youth's assigned sex, ethnicity-race, and prior prosocial behavior, path analyses revealed distinct pathways across ELA subtypes. A significant path from relational ELA to decreased prosocial behavior was mediated by lower affective empathy, aligning with deficit-based frameworks of adversity. However, consistent with strength-based perspectives, a significant path from biological ELA to increased prosocial behavior was mediated by higher affective empathy. Neither environmental ELA nor cognitive empathy was associated with prosocial behavior. CONCLUSIONS: Future research should explore socialization factors and interventions that enhance affective empathy among adolescents with biological and relational ELA, while considering multiple forms of prosocial behavior (e.g., helping vs. comforting) and additional mechanisms that may underlie these observed pathways (e.g., sensitive parenting, motivation).