Background & aims: accumulating evidence shows that various sleep behaviors are related to metabolic dysfunction-associated fatty liver disease (MAFLD), and that diet plays an important role in both preventing and treating this condition. However, the overall effect of a healthy sleep pattern and its joint effect with diet on the risk of MAFLD remain unclear. The aim of this study is to explore the independent and combined effects of dietary and sleep patterns on the MAFLD risk. Methods: this population-based prospective cohort study was conducted in China with a sample size of 13 687 participants. MAFLD was diagnosed through abdominal ultrasound and international expert consensus. Five healthy sleep behaviors were identified to create a healthy sleep pattern, while factor analysis was used to determine dietary patterns. Cox proportional hazards regression was utilized to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results: during a total of 49 912 person-years of follow-up, 2977 new cases of MAFLD were identified. The adjusted HRs (95% CIs) of MAFLD in relation to the healthy sleep pattern score were 0.87 (0.78-0.97), 0.83 (0.75-0.92), and 0.77 (0.68-0.87) for scores of 3, 4, and 5, respectively, compared to participants with the lowest score (0-2). A higher intake of animal food (adjusted HR4th quartile vs. 1st quartile, 1.15, 95% CI, 1.03-1.27) and a lower intake of vegetables (adjusted HR4th quartile vs. 1st quartile, 0.88, 95% CI, 0.78-0.99) were associated with a higher risk of MAFLD. Participants who adhered to both healthy dietary and sleep patterns had the lowest MAFLD risk compared to those who followed only one or neither of them. Conclusions: a healthy sleep pattern, especially in combination with a healthy diet, was associated with a lower risk of MAFLD. Future prevention strategies for MAFLD should include consideration of sleep behaviors, in addition to the current recommendations.