Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a serine protease predominantly synthesized by the liver, with expression also found in the gastrointestinal tract, pancreas, kidneys, and central nervous system. PCSK9 is involved in regulating lipid metabolism with numerous molecular targets both inside and outside hepatocytes. In the liver, it mainly targets lysosomal degradation through binding to low-density lipoprotein receptor (LDLR) on the cell membrane surface, thereby increasing plasma levels of low-density lipoprotein cholesterol. PCSK9 has garnered widespread attention in familial hypercholesterolemia, atherosclerosis, myocardial infarction, cancer, and other diseases, which has accelerated the rapid development of PCSK9 inhibitors, and played a significant role in the treatment of hypercholesterolemia and reducing the risk of cardiovascular diseases. As research on PCSK9 deepens and the prevalence of chronic liver diseases increases, the relationship between PCSK9 and the development of chronic liver diseases is gradually being revealed. Given the aforementioned background, this article elaborates on the role of PCSK9 in various common chronic liver diseases in clinical practice, including alcoholic liver disease, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, viral hepatitis, and liver cancer, aiming to offer new perspectives for the clinical diagnosis and treatment of chronic liver diseases.