This study examines whether neighborhood demographic characteristics are associated with sleep health among Korean older adults and whether this association is moderated by neighborhood social cohesion. Data are drawn from the 2019 Seoul Survey Data (SSD) merged with various sources of contextual data to assess information on population loss, age structure and immigrant concentration at the Gu level (N=20,319). We defined poor sleep health as respondents reporting six hours or less of sleep (coded 1; otherwise 0) Results from multilevel logistic regression model indicated that older adults who live in neighborhoods with high levels of immigrant concentration are more likely to experience poor sleep health. However, this association was mitigated by neighborhood social cohesion, such that those who have high levels of neighborhood social cohesion appear to be less influenced by immigrant concentration. This study suggests that neighborhood social cohesion may play a buffering role in minimizing the negative influence of neighborhood immigrant concentration on sleep health among older adults in Korea. Social policy and intervention aimed at promoting social cohesion may help reduce further disparities in poor sleep health in later life.