Lactate, a byproduct of glycolysis, has evolved from being viewed as a waste product to a key metabolic substrate and signaling molecule. Recent research highlights its role in liver diseases, including liver fibrosis, non-alcoholic fatty liver disease (NAFLD), acute liver failure (ALF), and hepatocellular carcinoma (HCC). Lactate metabolism is crucial for liver function, with the liver having the highest lactate clearance rate. Abnormalities in lactate production, transport, and lactylation contribute to liver disease progression. Lactate and lactate metabolism-related genes (LMRGs) can predict liver disease prognosis. Targeting lactate production, regulating lactate transport, and modulating lactylation are potential therapeutic strategies for liver diseases. Lactate transport is mediated by monocarboxylate transporters (MCTs), particularly MCT1 and MCT4, which regulate lactate shuttling between cells. GPR81, a receptor for lactate, influences immune responses and energy metabolism. Lactate also regulates fatty acid metabolism and inflammatory responses. In liver diseases, lactate accumulation is associated with fibrosis, NAFLD, and HCC. Lactate metabolism is involved in the progression of these diseases, and targeting lactate metabolism may offer new therapeutic approaches. Lactate levels are used as prognostic indicators for liver disease, including ALF and cirrhosis. Lactate metabolism-related genes, such as LDHA, HK2, and MCTs, are potential biomarkers and therapeutic targets. Research indicates that modulating lactate metabolism can improve liver disease outcomes. Lactate and lactate metabolism are involved in the development of HCC, with lactate promoting tumor growth and resistance to therapy. Targeting lactate metabolism, including lactate production, transport, and lactylation, may provide new strategies for treating liver diseases. Further research is needed to fully understand the role of lactate and lactate metabolism in liver diseases and to develop effective therapeutic approaches.Lactate, a byproduct of glycolysis, has evolved from being viewed as a waste product to a key metabolic substrate and signaling molecule. Recent research highlights its role in liver diseases, including liver fibrosis, non-alcoholic fatty liver disease (NAFLD), acute liver failure (ALF), and hepatocellular carcinoma (HCC). Lactate metabolism is crucial for liver function, with the liver having the highest lactate clearance rate. Abnormalities in lactate production, transport, and lactylation contribute to liver disease progression. Lactate and lactate metabolism-related genes (LMRGs) can predict liver disease prognosis. Targeting lactate production, regulating lactate transport, and modulating lactylation are potential therapeutic strategies for liver diseases. Lactate transport is mediated by monocarboxylate transporters (MCTs), particularly MCT1 and MCT4, which regulate lactate shuttling between cells. GPR81, a receptor for lactate, influences immune responses and energy metabolism. Lactate also regulates fatty acid metabolism and inflammatory responses. In liver diseases, lactate accumulation is associated with fibrosis, NAFLD, and HCC. Lactate metabolism is involved in the progression of these diseases, and targeting lactate metabolism may offer new therapeutic approaches. Lactate levels are used as prognostic indicators for liver disease, including ALF and cirrhosis. Lactate metabolism-related genes, such as LDHA, HK2, and MCTs, are potential biomarkers and therapeutic targets. Research indicates that modulating lactate metabolism can improve liver disease outcomes. Lactate and lactate metabolism are involved in the development of HCC, with lactate promoting tumor growth and resistance to therapy. Targeting lactate metabolism, including lactate production, transport, and lactylation, may provide new strategies for treating liver diseases. Further research is needed to fully understand the role of lactate and lactate metabolism in liver diseases and to develop effective therapeutic approaches.