<p>Older migrants in megacities face unique challenges in social cohesion due to the double jeopardy of “age” and “mobility”, both of which exacerbate loneliness. However, there is no evidence focusing on the role of community social cohesion in reducing loneliness among them. This study aimed to examine the association between community social cohesion and loneliness among older migrants in megacities of China. Data were obtained from a survey conducted between August and October 2022 in Beijing, China. Community social cohesion was measured using the Community Integration Measure (CIM), and loneliness was measured using the revised University of California at Los Angeles (UCLA) Loneliness Scale. We employed linear regression models to examine the relationship between community social cohesion and loneliness, as well as the moderating roles of individual socioeconomic resources. Additionally, path analysis was performed to investigate possible mechanisms. Our study identified a negative association between community social cohesion and loneliness (β = -3.49, 95% CI=-4.10, -2.88). Moreover, we found that individual socioeconomic resources played moderating roles in this association. Furthermore, community social cohesion mainly influenced later-life loneliness through the mechanism of social participation (social-recreational activities: β=-0.17, 95% CI=-0.31, -0.04; mutual-aid activities: β=-0.18, 95% CI=-0.29, -0.06). We highlighted the advantages of enhanced community social cohesion in alleviating loneliness among older migrants. Future policies and interventions should aim to encourage greater engagement in social activities among this population. Importantly, it is crucial to adopt various strategies for constructing community social cohesion for older migrants with different socioeconomic resources.</p>