Aim: This study examined the relationship between Helicobacter pylori (H. pylori) and metabolic dysfunction-associated fatty liver disease (MAFLD) and concurrently evaluated their association with all-cause mortality risk. Methods: Data were extracted from the Third National Health and Nutrition Examination Survey, which included 5,073 participants with available H. pylori IgG serology [enzyme-linked immunosorbent assay (ELISA)] results and mortality data. Logistic regression was used to assess the relationship between H. pylori seropositivity and MAFLD risk, while Cox proportional hazards regression was used to evaluate all-cause mortality risk, with adjustment for confounders. Results: Among 5,073 participants, 2,394 (47.2%) tested positive for H. pylori and 1,610 (31.7%) had MAFLD; during a median follow-up of 28.8 years, 1,891 deaths occurred (overall mortality rate 37.3%). H. pylori-seropositive individuals exhibited significantly higher mortality rates than seronegative individuals (43.5% vs. 31.7%, P < 0.001). Multivariate logistic regression confirmed H. pylori seropositivity as an independent risk factor for MAFLD [adjusted odds ratio (OR) = 1.282, 95% confidence interval (CI): 1.126-1.459, P < 0.001]. Multivariate Cox regression revealed that H. pylori seropositivity independently increased mortality risk (adjusted HR = 1.253, 95%CI: 1.139-1.379, P < 0.001), which was consistent across the MAFLD and non-MAFLD subgroups. Kaplan-Meier analysis corroborated significant survival divergence (log-rank, P < 0.001). Conclusion: This study indicates that H. pylori seropositivity is independently associated with a higher prevalence of MAFLD and greater mortality risk in community-dwelling individuals.