Abstract: Objective To investigate the relationship between thyroid hormones levels and frailty in patients with type 2 diabetes mellitus （T2DM）. Methods Data were obtained from a cross-sectional study, which was a follow-up of the METAL study （a 5-year community-based follow-up study on risk factors for chronic complications of diabetes） conducted from April to June 2023. The study included 897 adult patients with T2DM from 11 communities in Shanghai. The degree of frailty was assessed using the frailty phenotypes, which included weight loss, fatigue, reduced physical activity, decreased walking speed, and reduced grip strength. General information of participants was recorded, and the levels of thyroid hormones free triiodothyronine （FT₃）, free thyroxine （FT₄）, and thyroid-stimulating hormone （TSH） and thyroid antibodies thyroglobulin antibody （TgAb） and thyroid peroxidase antibody （TPOAb） were measured. Multivariate logistic regression analysis was used to examine the relationship between thyroid hormone levels and frailty phenotype. Results After adjusting for age, gender, body mass index （BMI）, smoking status, presence of hypertension or heart failure, duration of diabetes and glycated hemoglobin （GHbA_1c）, multivariate logistic regression analysis showed that FT₃ levels was the protective factor with weight loss （OR = 0.71, 95% CI 0.51-0.99） and low grip strength （OR = 0.61, 95% CI 0.43-0.86） （all P < 0.05）. Conclusions FT₃ levels are negatively correlated with weight loss and low grip strength in patients with T2DM, suggesting that low FT₃ levels may be associated with an increased risk of frailty in this population.