ObjectivePrevious work investigating the impact of childhood trauma on substance use and co-occurring psychiatric disorders has primarily been conducted in adults or on specific trauma types. This limits understanding of traumas impact in childhood and how different types of traumas play a role. We sought to characterize substance use in a sample of trauma-exposed youth in the context of psychiatric comorbidities. Method1152 youth from the Texas Childhood Trauma Research Network (TX-CTRN) that were exposed to at least one trauma meeting DSM-5 Criterion A were assessed for current substance use and psychiatric diagnoses. Latent class analysis was used to identify patterns of substance use. To characterize these patterns, we examined if demographics, number of trauma types experienced, or childhood psychiatric disorders predicted class membership. ResultsWe identified four primary patterns of substance use: Non-use (66.1%), predominantly alcohol use (19.7%), predominantly cannabis use (4.5%), and polysubstance use (9.7%). Compared to the non-users, polysubstance users tended to be older, Non-Hispanic White, have experienced more types of trauma. They were also more likely to have fulfilled diagnostic criteria for suicidality and ADHD. Comparisons among the substance using classes were more nuanced. ConclusionThe findings highlight the need for universal assessments of trauma, substance misuse, and mental health symptoms in youth as the presence or absence of their co-occurrence has implications for treatment.