Background/Objectives: Metabolic dysfunction–associated steatotic liver disease (MASLD) has emerged as a major global etiology of chronic liver disease. However, the prognostic impact of MASLD in patients with non-B, non-C HCC (NBNC-HCC) following curative resection remains poorly defined. This study aimed to evaluate the prognostic significance of histologic SLD and MASLD-related components in this growing patient population. Methods: We retrospectively reviewed consecutive patients with NBNC-HCC receiving curative-intent hepatectomy between 2014 and 2023, excluding those with viral hepatitis or significant alcohol use. MASLD was defined as hepatic steatosis (≥5%) combined with at least one cardiometabolic risk factor (obesity, type 2 diabetes, dyslipidemia, or hypertension). Primary endpoints were overall survival (OS) and recurrence-free survival (RFS). Cox proportional hazards models were used to identify independent prognostic factors. Results: 169 (61.7%) patients fulfilled MASLD criteria. The MASLD group showed significantly better RFS (p = 0.039) and OS (p = 0.016). Notably, after multivariate adjustment, histologic SLD remained independently associated with reduced mortality (HR 0.55, 95% CI 0.32–0.93; p = 0.027), while MASLD status was attenuated. Subgroup analysis revealed that this survival benefit was most pronounced in non-cirrhotic patients (p = 0.027 for OS). Patients with MASLD also exhibited lower liver-related mortality (p = 0.028). Conclusions: Steatotic liver disease was independently associated with improved survival in NBNC-HCC patients undergoing curative hepatectomy, particularly in non-cirrhotic individuals. Given the increasing prevalence of MASLD, incorporating hepatic steatosis, metabolic components, and fibrosis status into risk stratification may help improve postoperative management in this distinct subgroup.