South Korea has experienced the highest age-standardized suicide rates, especially among the elderly, among OECD countries over the past two decades. The Korean elderly, aged 65 or older, have faced extremely high poverty rates, which seem to be strongly linked to increased suicide mortality in this society. Community social capital, defined as the level of interpersonal trust and mutual support, is well-known to affect various health outcomes, including mental health. This ecological study aims to examine whether a higher level of community social trust can mitigate the impact of area-level poverty on the risk of suicide among the elderly. We included 260 counties (Si-gun-gu) with 5-year average suicide rates during the period of 2015 to 2019. The poverty rates among the elderly and the level of social capital for these 260 counties were measured among approximately 900 individuals aged 19 or older. These participants were randomly selected from each county, totaling 200,000 participants, in the 2014 Korea Community Health Survey (KCHS). The ecological analysis revealed that areas with higher elderly poverty rates were associated with increased suicide rates among the elderly (b=0.26, 95% CI 0.22~0.32). When the counties were stratified into three groups based on the level of community social capital, the effect of elderly poverty rates on suicide rates seemed to diminish in areas with higher social trust (b=0.14, 95% CI 0.0~0.3), compared to areas with lower social trust (b=0.53, 95% CI 0.42~0.63). This study found that the association between poverty and suicide was less pronounced in counties with higher levels of social capital. Further studies are needed to investigate how community-level social capital affects the individual risk of suicide among the elderly residing in areas with higher social capital.