<p>This study aimed to investigate (1) the mediating role of psychological distress in the association between online social support and life satisfaction and (2) the chain mediating role of resilience and psychological distress in the association between online social support and life satisfaction among university students at risk of Facebook addiction in Vietnam. 1198 university students were investigated with the psychological distress scale, resilience scale, life satisfaction scale and online social support scale. The results indicated that (1) Online social support significantly positively predicted life satisfaction; (2) psychological distress mediated the link between online social support and life satisfaction; (3) resilience and psychological distress chain mediated the association between online social support and life satisfaction. These findings contribute to our understanding of the complex interplay between online social support and the life satisfaction of university students at risk of Facebook addiction, emphasizing the potential benefits of increasing online social support to boost resilience, decrease psychological distress, and ultimately improve their life satisfaction.</p>