Suicide is a leading cause of death in young adulthood. Identifying early prevention targets to reduce later suicide is a public health priority. Impulsivity and aggression in early childhood may represent actionable early prevention candidate endophenotypes for later suicidal behavior. Our objective is to to understand the association of aggression and impulsivity trajectories with mental health outcomes to inform future prevention efforts. Participants were part of a longitudinal cohort of a preventative intervention trial (n = 597) and predominantly Black. They were assessed for aggressive and impulsive behaviors yearly in 1st-3rd and 6th-12th grades, and provided mental health data via self-report beginning in 6th grade. Longitudinal latent profiles of aggressive and impulsive behaviors were derived for males and females and used to determine whether profiles was associated with lifetime suicide attempt and meeting diagnostic criteria for major depressive disorder. Two impulsivity and aggression classes were found for males, characterized by low behaviors or moderate to high behaviors across development. Three classes were found for females, one of which was characterized by an undulating pattern of behaviors. For females, the class of severe behaviors was associated with significant risk of suicide attempt (Wald = 6.01, p = 0.05). No relationship was found for males or for MDD diagnosis. An endophenotype model of impulsivity and aggression in predicting later suicide attempt was supported in females, but not males. Results underscore the importance of evaluating sex differences in suicide research and the potential identification of females at risk for later suicidal behavior in school settings.