The burden of cardiometabolic diseases (CMDs), defined as stroke, coronary artery disease, and diabetes mellitus, continues to pose a global challenge. Sleep duration has been linked to cardiovascular health. However, there is a lack of focused investigations on CMDs in underdeveloped areas of China. This study aimed to examine the relationship between sleep duration and CMDs among residents from southwest China. This large cross-sectional study screened data from the National Key Research and Development Program (2018YFC1311400). Based on sleep duration reported through a standardized questionnaire, encompassing the sleep patterns of the past five years, participants were classified into three groups: <6, 6-8, >8 hours. Baseline characteristics were compared, and Poisson regression models were used to assess the relationship between sleep duration and CMDs. Subgroup analysis was conducted based on age and gender. This study included 28,908 participants with an average age of 65.6 ± 10.0 years, of whom 57.6% were female. The overall prevalence of CMDs was 22.6%. After multivariate adjustments, the prevalence ratios (PR) (95% CI) for CMDs across the three groups (6-8h, <6h and >8h) were: reference, 1.140 (1.068-1.218), 1.060 (0.961-1.169) (P for trend =0.003), respectively. The subgroup analysis revealed that among older females, a longer sleep duration (>8h) was also associated with an increased prevalence risk of CMDs, with PR 1.169 (1.001-1.365) (p=0.049). A shorter sleep duration (<6 hours) was associated with an increased risk of CMDs in the general population, while a longer sleep duration (>8 hours) also raised the prevalence risk among older females.