Maltreated youth tend to enter into the juvenile justice system at younger ages than their non-maltreated counterparts. Early involvement in the juvenile justice system compounds maltreated youth’s risk of adverse developmental outcomes, including serious and continued offending. This study prospectively examined risk factors of first time delinquency for maltreated youth between ages 9 and 14. Using integrated statewide administrative data from Minnesota, this study followed 5002 students with maltreatment histories in 3rd grade for their first adjudication of delinquency over a 6-year period. Cox proportional hazard regression was employed to model time to youth’s first time delinquency, and to identify risk factors. Approximately 7% of maltreated youth (n = 332) were adjudicated as delinquent during this period. The results indicated significant risk factors for early onset of delinquency in maltreated youth: being male (HR = 1.87, 95% CI 1.45, 2.40), belonging to particular racial minority groups, especially Black (HR = 1.80, 95% CI 1.36, 2.39), Native American (HR = 2.34, 95% CI 1.61, 3.39, and Hispanic (HR = 1.73, 95% CI 1.10, 2.71), diagnoses of emotional/behavioral disabilities (HR = 1.96, 95% CI 1.30, 2.93), receiving an out-of-school suspension (HR = 1.53, 95% CI 1.04, 2.25), and experiencing more than three previous maltreatment incidents (HR = 2.02, 95% CI 1.54, 2.64). Solutions for maltreated youth who cross over to the juvenile justice system clearly require interventions that are developmentally sensitive and simultaneously address risk factors across multiple ecological levels.