Frailty and type 2 diabetes mellitus (T2DM) can occur concurrently and are increasingly prevalent in older populations. There is a marked variability in frailty progression between men and women. This study aimed to investigate sex differences in the prevalence and factors associated with frailty in older outpatients with T2DM. This multicentre cross-sectional study included 638 outpatients (aged ≥ 60 years; median age 71 years [interquartile range, 66-77]; male, 55.5%) and was conducted from January 2019 to July 2020. Frailty was assessed using the Fried frailty phenotype. Factors associated with frailty were assessed using a logistic regression analysis. The overall frailty prevalence was 28.2% (men, 26.8%; women, 29.9%; P = 0.388). In the adjusted model, the factors associated with greater odds of being frail were older age (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.05-1.11; P < 0.001) and body mass index (BMI) less than 20 kg/m(2) (OR, 1.96; 95% CI, 1.16-3.32; P = 0.012). Higher education (OR, 0.64; 95% CI, 0.42-0.98; P = 0.041) and productive work (OR, 0.11; 95% CI, 0.03-0.36; P < 0.001) were protective factors against frailty. Frailty was associated with all four factors in women, but only with older age and productive work in men. Our study found that the prevalence of frailty in older outpatients with T2DM was 28.2%, though not significantly different between men and women. While older age and BMI less than 20 kg/m(2) can increase the odds of frailty, and higher education and productive work can decrease the odds of frailty in women, only age and productive work were associated with frailty in men with T2DM.