We aimed to explore the relationship between social capital (SC) and frailty, and the mediation role of depressive symptoms in this relationship. A cross-sectional study among 2,591 older adults aged ≥60 years old was conducted from September 2020 to May 2021. SC, depressive symptoms, and frailty were measured using the social capital scale, the 9-item patient health questionnaire, and the FRAIL scale, respectively. The mediation model was tested by Bootstrap PROCESS. After controlling for socio-demographical covariates, the SC was negatively correlated with frailty (r = -0.07, P = 0.001), and depressive symptomatology (r = -0.08, P