Background Most population-based sexual health research in China excludes older adults. To fill the gap, this study aims to characterise sexual dissatisfaction among people aged 50years or older from a nationwide, population-representative sample and to explore its association with physical, mental, and self-reported overall health indicators. Methods Data were collected as part of the China Family Panel Studies in 2020, led by the Institute of Social Science Survey of Peking University. Multivariable logistic regressions with robust estimators were used to investigate the association between sexual dissatisfaction and health indicators and potential demographic confounders. Results Among the 8222 partnered Chinese adults aged 50years or older (median age: 59, IQR: 54-66, 47% identified as women), 78% (6380/8222) reported being satisfied or very satisfied in their sex life. After adjusting for demographic variables, poor self-rated health status (aOR: 1.59, 95% CI: 1.42-1.77), experiencing depression symptoms (aOR: 2.02, 95% CI: 1.80-2.26), and having chronic diseases (aOR: 1.20, 95% CI: 1.07-1.36) were positively associated with sexual dissatisfaction in multivariable analyses. Among sociodemographic factors, younger age, female gender, and education level at senior high school or above were more likely to experience sexual dissatisfaction (all P Conclusion Based on our sample, more than one in five Chinese adults aged 50years or older might face sexual dissatisfaction. Comorbidities common in older age likely exacerbate sexual dissatisfaction. Greater attention to sexual satisfaction research and sexual health programs among older adults is needed with respect to gender differences and chronic disease comorbidities.