Hepatocellular carcinoma (HCC) is the most common subtype, accounting for about 90% of all primary liver cancers. The liver is rich in a large number of immune cells, thus forming a special immune microenvironment, which plays a key role in the occurrence and development of hepatocellular carcinoma. Nowadays, tumor immunotherapy has become one of the most promising cancer treatment methods. Immune checkpoint inhibitors (ICIs) combined with VEGF inhibitors are listed as first-line treatment options for advanced HCC. Therefore, the search for a potential biomarker to predict the response to immunotherapy in HCC patients is urgently needed. The G protein-coupled receptor 55 (GPR55), a lysophosphatidylinositol (LPI) receptor, has recently emerged as a potential new target for anti-tumor therapy. Previous studies have found that GPR55 is highly expressed in breast cancer, pancreatic cancer, skin cancer and cholangiocarcinoma, and is involved in tumor proliferation and migration. However, the role and mechanism of GPR55 in HCC has not been elucidated. Therefore, this article discusses the clinical significance of GPR55 in HCC and its correlation with the immune response of HCC patients, so as to provide theoretical basis for improving the prognosis of HCC.