OBJECTIVES: Loneliness at older ages is a significant public health concern, and promoting participation in neighborhood events and activities may be a possible avenue for alleviating loneliness among older adults. However, there remains a scarcity of empirical research in this field. Addressing this knowledge gap, our study examined the association between frequency of neighborhood participation by older adults and their subsequent feelings of loneliness two years later, in a nationally representative longitudinal cohort of community-dwelling Singapore citizens and permanent residents aged 60 years and older. METHODS: We used two waves (2016-2017 and 2019) of data from the Transitions in Health, Employment, Social engagement, and Inter-Generational transfers in Singapore Study (THE SIGNS Study) (n=1,217). Frequent neighborhood participation was defined as participating in neighborhood committees, clubs, or events once a week or more, while loneliness was measured using the Three-item loneliness scale. To mitigate selection bias, we employed inverse probability-weighted regression adjustment to estimate the relationship between the frequency of neighborhood participation and loneliness. RESULTS: Our findings indicate that older adults who participated in neighborhood events frequently had a lower probability of loneliness at wave 2 compared to non-participants. Conversely, infrequent neighborhood participation at baseline did not demonstrate an association with loneliness at wave 2. DISCUSSION: Our findings suggest that a higher intensity of involvement in neighborhood activities may be necessary to achieve the benefits of participation. Our findings also highlight the potential of neighborhood-based interventions as a public health strategy to address loneliness in aging populations.