The Cardiometabolic Index (CMI) represents an innovative metric that encompasses abdominal obesity and lipid levels, offering a comprehensive assessment of cardiometabolic health. It is derived through the multiplication of the waist-to-height ratio by the triglyceride-to-high-density lipoprotein cholesterol ratio. Although obesity and blood lipid levels are known factors affecting sleep quality, the direct correlation between CMI and sleep quality has yet to be elucidated. This study uses NHANES data to explore the potential correlation between CMI and sleep quality. Our research employed a cross-sectional design, utilizing data from the National Health and Nutrition Examination Survey (NHANES) spanning 2011 to 2014. CMI was used as the exposure variable, with sleep quality assessed through three self-reported measures: trouble sleeping, sleep disorders, and sleep duration. We employed multivariate logistic regression models and linear regression model as well as subgroup analyses to explore the independent relationship between CMI and sleep quality. Additionally, interaction tests were conducted to examine differences across various subgroups. The study included 4298 participants, comprising 2134 males and 2164 females. There was a positive correlation between CMI and trouble sleeping (OR = 1.63, 95% CI 1.28-2.08) and sleep disorders (OR = 1.96, 95% CI 1.43-2.67), while there was a negative correlation between CMI and sleep duration (β = - 0.17, 95% CI - 0.31 to - 0.03), indicating that a higher CMI was associated with shorter sleep duration. Subgroup analyses and interaction tests revealed a consistently positive association between CMI and sleep difficulty across various populations, including gender, age, hypertension, diabetes, and cardiovascular disease history. However, the relationship between CMI and sleep disorders was more prominent among participants aged 50 and above. In American adults, a higher CMI is linked to an increased prevalence of sleep disturbances. In clinical practice, CMI can be considered as a supplementary factor in the assessment and management of sleep problems. Our study also provided new insights for improving sleep quality.