BACKGROUND: Sleep disorders (SDs), a public health concern, can lead to critical physiological conditions, and are associated with mental and behavior problems such as psychosocial stress, smoking, alcohol consumption, etc. This study aimed to investigate the cross-sectional associations between dentofacial deformities and sleep quality in young adults in China. METHODS: Data were collected from 2,479 young adults (aged 17-25 years) enrolled at Fudan University across various regions of China. Participants completed a self-reported questionnaire that included general information and the Pittsburgh Sleep Quality Index (PSQI) under standardized guidance. Dentofacial characteristics were examined by experienced orthodontists. Data analysis employed one-way ANOVA, student's t-test, chi-square tests, and multivariable logistic regression models. RESULTS: The study revealed a median PSQI score of 5.92 ± 1.66, with 16.3% of participants classified as SDs. Higher PSQI scores were reported by females, underweight individuals, and participants from southern regions. Among the subjects, 44.36% exhibited protruding profiles, 6.86% had concave profiles, and various dentofacial abnormalities were prevalent. Logistic regression analysis identified protruding lateral profiles (OR 1.93, 95% CI 1.18-3.16, p = 0.008) and anterior crossbite (OR 1.44, 95% CI 1.01-2.04, p = 0.043) as significant risk factors for SDs. Additionally, reduced anterior overbite was associated with a higher prevalence of SDs, while deep overbite acted as a protective factor. Moderate overbite demonstrated statistical significance (OR 0.51, 95% CI 0.35-0.76, p = 0.001). CONCLUSION: These findings suggest a significant association between dentofacial characteristics and sleep quality in young adults. Protruding facial profiles and anterior crossbites were identified as independent predictors for SDs. These findings underscore the importance of screening for SDs in individuals with dentofacial deformities and highlight the potential benefits of early correction of such dentofacial abnormalities to reduce the risk of SDs in adulthood.