BackgroundWhether healthy lifestyles mediate the association of socioeconomic status (SES) with mortality in older people is largely unknown.MethodsA total of 22,093 older participants (age ≥ 65 years) from 5 waves (2002–2014) of Chinese Longitudinal Healthy Longevity Survey cohort were included for analysis. Mediation analysis of lifestyles on the association of SES with all-cause mortality was conducted.ResultsDuring a mean follow-up period of 4.92 ± 4.03 years, 15,721 (71.76%) deaths occurred. Compared with high SES, medium SES increased the risk of mortality by 13.5% (HR [total effect]: 1.135, 95% CI 1.067–1.205,p< 0.001), and the total effect was not mediated by healthy lifestyles (mediation proportion: − 0.1%, 95% CI − 3.8 to 3.3%,p= 0.936). The total effect when participants of low SES were compared with participants of high SES was HR = 1.161 (95% CI 1.088–1.229,p< 0.001) for mortality, and the total effect was modestly mediated through healthy lifestyles (mediation proportion: − 8.9%, 95% CI − 16.6 to − 5.1%,p< 0.001). Stratification analyses by sex, age and comorbidities, as well as a series of sensitivity analyses indicated similar results. In addition, mortality risk showed a downward trend with increased number of healthy lifestyles within each SES level (allpfor trend < 0.050).ConclusionPromotion of healthy lifestyles alone can only reduce a small proportion of socioeconomic inequity-related mortality risk in older Chinese people. Even so, healthy lifestyles are important in reducing the overall mortality risk within each SES level.Supplementary InformationThe online version contains supplementary material available at 10.1007/s44197-023-00095-3.