We aimed to investigate the effect of sleep problems, depression, and cognitive processes on suicidal risk among 460 young adults. They completed self-report questionnaires assessing suicidal behavior, sleep quality, depressive symptoms, emotion regulation, rumination, and impulsivity. Suicidal participants exhibited higher rates of depressive symptoms, sleep problems, expressive suppression, rumination, and impulsivity. A confirmatory factor analysis model revealed pathways to suicidal risk that showed no direct pathways between sleep problems and suicidal risk. Instead, sleep was related to suicidal risk via depression and rumination, which in turn increased suicidal risk. These results suggest that addressing sleep problems will be useful in either the treatment or prevention of depressive and rumination symptoms and reduction in suicidal risk.