Suicide in later life is a significant public health problem around the world—a problem that will increase in magnitude in the coming years with the impact of population aging. Adults age 70 and older have higher suicide rates than younger groups worldwide in both lower-income and higher-income countries. While suicide rates tend to increase with age, suicide in later life is not an expected or normative response to stressors that accompany the aging process. Instead, a constellation of risk factors places an older adult at elevated risk for suicide. These factors can be remembered as the Five D’s: psychiatric illness (primarily depression); functional impairment (also called disability, often associated with dependency on others); physical illness (particularly multiple comorbid diseases); social disconnectedness (including social isolation, loneliness, family conflict, and feeling like a burden); and access to lethal (deadly) means. The greatest risk occurs when multiple domains of risk converge in a given individual. Approaches to prevention can address the Five D’s. Given that older adults are reluctant to seek out mental healthcare and that standard primary care practice cannot easily provide it, models of primary care-based integrated care management for mental disorders, including in older adulthood, have been developed, rigorously tested, and widely disseminated. These models play an important role in suicide prevention by integrating treatment for physical and mental illness. Upstream, selective prevention strategies that target disconnectedness—such as engaging older adults as volunteers—may serve to reduce disconnectedness and thereby reduce suicide risk. Universal prevention strategies that involve growing the geriatric workforce may address disability by increasing older adults’ access to medical and social service providers with expertise in improving physical, cognitive, and social functioning, as well as improving quality of life. Addressing ageism and building age-friendly communities that use strategies to integrate older adults into society and promote social participation hold promise as universal prevention strategies. Ultimately, effective suicide prevention strategies for older adults must focus on improving quality of life as well as preventing suicide: strategies such as psychotherapy and medication for psychiatric disorders must be supplemented by prevention strategies for older adults give at all ages in addition to treating psychiatric disorders and suicidal thoughts is needed to address the problem of suicide in later life.