Depressive disorders affect a rising number of youth and are associated with significant comorbidities and adverse psychosocial outcomes. Despite the critical need for effective assessment tools, existing measures for youth depression are often limited by cost, length, and a narrow conceptualization of depressive symptoms. This study adapts the Overall Depression Severity and Impairment Scale (ODSIS) for youth (ODSIS-Y), creating a brief, freely accessible caregiver- and self-report measure of pediatric depression severity, frequency, and impairment. The psychometric properties of the ODSIS-Y were evaluated in a sample of 235 children and adolescents (aged 5–18; 50.6% female; 69.2% race/ethnicity identity other than Non-Hispanic White) seeking treatment for internalizing disorders and their caregivers. Confirmatory factor analyses supported a single-factor structure for both caregiver- and self-report versions of the ODSIS-Y. Convergent validity was established through significant correlations with supported measures of depression, anxiety, and irritability. Divergent validity analyses indicated lower associations with externalizing symptoms. The ODSIS-Y offers a practical, reliable, and valid tool for assessing youth depression across various settings. Its brief format supports routine monitoring and clinical utility, addressing a significant gap in the available measures for youth depression. Further research is needed to establish clinical cutoffs, assess sensitivity to change over time, and evaluate psychometric properties of the ODSIS-Y among more diverse youth and clinical settings.