This study used Washington statewide administrative data to document the prevalence and trend of trauma history, suicidality, and mental health problems among all youth ordered to probation for the first time between 2011 and 2015. We also examined the extent to which trauma and mental health problems were associated with youth suicide risk during this time.More than 16,500 youth started probation (2011–2015) and received a standardized risk assessment. We used descriptive statistics to assess the prevalence of trauma history, suicidality, mental health problems, and overall risk to reoffend. We then used multilevel logistic regression models (youth within counties) to assess each measure's association with suicidality.About 80% of the youth had a history of at least one traumatic experience. As fewer youth started probation for the first time each year, the prevalence of trauma, suicidality, mental health problems, and overall risk to reoffend increased. Trauma, mental health, and overall risk were significantly associated with suicide risk among probation youth.This epidemiological study is expected to motivate discussion around the best ways to integrate trauma-informed care and suicide prevention in the juvenile justice system.