Background <p>Metabolic dysfunction-associated steatotic liver disease (MASLD) is a prevalent chronic disease, but it remains unclear whether it is related to dietary folate. This research sought to investigate the association between dietary folate and MASLD.</p> Methods <p>This cohort study utilized the UK Biobank (UKB) database (<i>N</i> = 58,047). Dietary folate intake was assessed using an online dietary questionnaire, and MASLD was ascertained through International Classification of Diseases, Tenth Revision (ICD-10). Cox proportional hazard regression, mediation analysis and restricted cubic splines (RCS) were employed to investigate the association and dose-response relationship between dietary and MASLD. The stability of findings was verified by stratified analyses and sensitivity analyses.</p> Results <p>Dietary folate intake was observed to be negatively associated with MASLD in cohort studies. During a median follow-up of 12.18 years, 691 cases of MASLD occurred. The risk of MASLD decreased by 24% (HR = 0.76, 95% CI: 0.59–0.97) among the participants in the highest dietary folate intake relative to lowest quartile. The protective effect was more pronounced in participants aged &lt; 60 years (HR = 0.63, 95% CI: 0.45–0.89), male (HR = 0.63, 95% CI: 0.44–0.89), and obese participants (HR = 0.68, 95% CI: 0.48–0.95). The research results remained robust in the sensitivity analyses that excluded participants with ≤ 2 years of follow-up time, extremely folate intake, and other conditions. C-reactive protein (CRP) explained 6.56% of the association between dietary folate and MASLD. The dietary folate intake had an L-shaped relationship with the risk of MASLD (<i>P for nonlinearity</i> = 0.003).</p> Conclusions <p>Moderate folate intake (approximately 300&#xa0;µg) may reduce the risk of MASLD, suggesting that promoting folate-rich diets may be a viable and cost-effective strategy for MASLD prevention.</p>