Monascus vinegar (MV) is a typical fermented food with various health-promoting effects. This study aimed to evaluate the role of MV in alleviating high-fat-diet-induced inflammation in rats with hyperlipidemia and elucidate the possible regulatory mechanisms. In the study, serum lipid profiles, liver pathology and liver inflammatory cytokines were analyzed in hyperlipidemia rats with MV (0.5 mL/kg mb, 2 mL/kg mb). Results showed that the administration of MV alleviated dyslipidemia by decreasing the serum and liver levels of triglyceride and total cholesterol. Increase in hepatic lipase and carnitine palmitoyl transferase 1 (CPT-1) levels and decrease in hepatocyte steatosis, nephritis, and intestinal tissue injury in the HD group showed that high-dose MV can significantly suppress hepatic lipid accumulation and steatosis. In addition, compared with the model (MOD) group, the HD group showed significantly down-regulated the level of serum or hepatic alanine aminotransferase (ALT), aspartate aminotransferase (AST), CPT-1, interleukin (IL)-2, IL-6, IL-12, and tumor necrosis factor α (TNF-α). Moreover, the HD group showed repressed hepatic nuclear factor κB (NF-κB) pathway and inactivated phosphatidylinositol 3-kinase (PI3K)/ protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway mitigated liver inflammation. Similar results were obtained from cell experiments. Collectively, these findings revealed that MV might attenuate high-fat-diet-induced inflammation by inhibiting the NF-κB and PI3K/Akt/mTOR pathways.