Fatty liver disease, encompassing both alcoholic (AFLD) and non-alcoholic (NAFLD) forms, represents a significant global health burden. NAFLD, in particular, is the most prevalent chronic liver disease and is closely linked to obesity, type 2 diabetes mellitus, and metabolic syndrome. The disease spectrum ranges from benign hepatic steatosis to non-alcoholic steatohepatitis (NASH), which can progress to cirrhosis and hepatocellular carcinoma. Biochemical markers play a pivotal role in the non-invasive diagnosis, prognosis, and monitoring of fatty liver disease. These include traditional liver enzymes such as ALT and AST, as well as advanced markers like cytokeratin-18 (CK-18), fibroblast growth factor 21 (FGF21), and composite indices like the NAFLD fibrosis score. Emerging omics technologies and biomarker panels hold promise for improving early detection and personalized treatment. This document provides a comprehensive overview of fatty liver pathophysiology and the utility of biochemical markers in its clinical management.