Prior work has established bivariate associations between suicidal thoughts and behaviors, trauma exposure and sleep disturbance broadly. Specifically, this study tested whether fear of sleep and sleep quality mediated the association between trauma exposure and suicide attempt. Participants (N = 100) were adolescents admitted to an inpatient psychiatric program for suicidality. Trauma exposure history was retrieved from admission notes and participants completed self-report surveys assessing sleep quality, fear of sleep and number of suicide attempts within the previous month. Structural equation modelling was used to investigate the relationships between childhood trauma, fear of sleep, sleep quality, and suicide attempt. Path analysis was used to investigate the indirect effects from trauma exposure to suicide attempt through fear of sleep, and sleep quality. Path analysis revealed a significant indirect effect from trauma exposure to suicide attempt through fear of sleep and sleep quality. Our findings suggest that a significant portion of the association between trauma exposure and suicide attempts in adolescence may be explained by the negative impact of trauma exposure on sleep. Fear of sleep may increase the risk of a suicide attempt by negatively impacting sleep quality. Future studies should investigate whether interventions targeting sleep and fear of sleep reduce the association between trauma and suicide attempt.