Polymorphisms in the oxytocin receptor gene are commonly associated with prosocial behaviors in the extant literature, yet their role in antisocial behaviors has rarely been explored, particularly during the transition from adolescence to early adulthood. We examined a prospective cohort (N = 404), collecting youth, mother, and clinician reports of conduct-disordered and antisocial behavior at ages 15 and 20. The oxytocin receptor gene rs53576 polymorphism was hypothesized to interact with social stress to predict antisocial outcomes. Structural equation modeling results revealed a significant main effect at age 15 (p = .025); those with the G allele exhibited higher levels of conduct problems. Structural equation modeling revealed a significant Gene × Environment interaction at age 20 (p = .029); those with the G allele who experienced high social stress exhibited higher levels of antisocial behavior. Heterozygous (AG) grouping models were compared, and parameter estimations supported G dominant groupings. These novel findings suggest that rs53576 polymorphisms may influence social salience and contribute to risk for antisocial outcomes, particularly under conditions of high social stress.