Objective In this paper, we examined the relationship between insomnia symptoms and suicidality in a national sample of US adolescents, while controlling for several psychiatric disorders that are known to be associated with suicidality. Additionally, we examined whether insomnia symptoms interact to affect any suicidality variables. Methods Study participants were 10,123 adolescents between the ages of 13Ð18 from the National Comorbidity Survey Ð Adolescent Supplement (NCS-A). Results In bivariate analyses, all insomnia symptoms (i.e., difficulty falling asleep, difficulty staying asleep, and early morning awakening) were associated with suicide ideation, plan and attempts. In multivariate analyses, controlling for substance use, mood and anxiety disorders, as well as important covariates, difficulties falling and staying asleep had a significant relationship with 12-month and lifetime suicide variables while early morning awakening did not. Conclusions Two of the three insomnia symptoms had a significant association with suicide thoughts and plan even after controlling for psychiatric disorders that were known to affect suicidality. Having trouble falling sleeping or staying asleep had both direct and indirect relationships (via substance use, mood and anxiety disorders) on suicidal behavior. Assessment and treatment of sleep disturbances may reduce the risk for suicidality in adolescents.