Given the significant costs of suicidal behavior for society, suicide prevention is one of the most urgent issues for most countries. By considering suicidal ideation as a strong indicator of suicide, this paper examines how Internet use influences suicidal ideation and its underlying mechanisms in the context of older adults. Synthesizing the interpersonal theory of suicide with prior literature on Internet use, this study explains that Internet use can reduce suicidal ideation through enhanced social belongingness. Our results using data from 6,056 older adults show that Internet use is negatively associated with suicidal ideation in older adults. The present study further highlights the mediating role of social connectedness (i.e., perceived loneliness and social relationship satisfaction) as an underlying mechanism between Internet use and suicidal ideation. Contributions and practical implications for addressing elderly suicidal problems and future works are discussed