Sleep disturbances, particularly insomnia, nightmares, and excessive daytime sleepiness (EDS), are significant, proximal, and modifiable risk factors for suicidal ideation and behaviors (SIB) and could be targeted for preventative interventions. In this chapter, we review the evidence supporting the association of insomnia, nightmares, and EDS with SIB. We also describe these sleep disturbances in the general population, as well as their association with psychiatric disorders. A PubMed search was conducted to identify the relevant literature. Insomnia is very frequent across mental disorders, but SIB patients are particularly exposed. Specific interventions focused on insomnia are useful in contending suicidal ideation. Nightmares seem to constitute an independent risk factor for SIB, beyond insomnia, particularly in young people and when experienced frequently. The evidence regarding the association of EDS and SIB is less clear and probably explained by the reduction of health-related quality of life and comorbid depression. The mechanisms underlying the relationship between sleep disturbances and SIB as well as the role of potential confounders and future perspectives in this field are also discussed.