Objective To investigate the mediating role of depression in the association between multidimensional social deprivation and frailty among the elderly.Methods A total of 533 elderly individuals were enrolled from a district in Chengdu using a convenience sampling method.The participants responded to a questionnaire survey.Spearman rank correlation coefficient was employed to assess the correlations among social deprivation,depression,and frailty.MacKinnon's product-of-coefficients method was used to test the significance of the mediating effect of depression between social deprivation and frailty.Results Among the participants,the average score for social deprivation among the participants was 48.9±7.1,the depression detection rate was 12.8%,and the frailty incidence rate was 8.4%.Social deprivation was positively correlated with frailty(r=0.212,P＜0.001)and depression(r=0.399,P＜0.001),while depression was positively correlated with frailty(r=0.248,P＜0.001).The results of the mediation analysis showed that depression partially mediated the relationship between social deprivation and frailty(P＜0.05),accounting for 64.95%of the mediation effect.Specifically,depression partially mediated the relationship between socio-economic status,comprehensive feeling,and frailty(P＜0.05),accounting for 70.30%and 64.76%of the mediating effect,respectively.Depression fully mediated the relationship between family and social support,political and social participation dimensions,and frailty(P＜0.05).Conclusion Social deprivation can influence frailty in elderly people,with depression partially mediating this association.