• Court-involved, non-incarcerated youth report mental health symptoms at a high rate.
• More serious delinquency predicts clinically meaningful externalizing problems.
• Delinquency severity does not predict internalizing problems.
• Internalizing problems were high for boys and girls across delinquency severities.
Youth involved in the justice system meet criteria for psychiatric disorders at much higher rates than youth in the general population and a large body of research has established a relationship between mental health problems and delinquency or recidivism. However, only limited research has examined the relationship between specific types of psychopathology and specific patterns or types of delinquency for justice-involved youth and only a single study has explored the relationship between psychopathology and delinquency among youth with psychiatric diagnoses receiving mental health treatment. We examined the relationship between severity of offending and internalizing and externalizing symptoms among court-involved, non-incarcerated youth referred for mental health treatment. Over half of youth and over two-thirds of parents reported youth symptomatology at the 93rd percentile or above for internalizing symptoms, externalizing symptoms, or both. We found that youth engaged in serious or violent delinquency are more likely to have externalizing problems but that internalizing symptoms were equally high across youth committing minor, moderate, and serious delinquent acts. Findings from this study support the need for future research exploring the nuances of relationships between psychiatric disorder and patterns of delinquency, which can provide helpful information to justice system stakeholders in identifying youth needs.