BACKGROUND Hepatocellular carcinoma (HCC) is a difficult cancer to manage due to its highly invasive and metastatic nature. AIM To investigate the molecular function of transmembrane channel-like 5 (TMC5) in vitro and in vivo, with the objective of identifying novel diagnosis and treatment targets for HCC. METHODS The expression of TMC in cancer and normal tissues, along with its correlation with HCC prognosis, was analyzed using the GENT2, GEPIA database, and Human Protein Atlas. COX analysis was conducted to assess the relationship between TMC5 expression and overall survival in TCGA-LIHC patients. Further experiments were conducted to investigate the effect of TMC5 in cancer progression through loss- and gain-of-function assays in vitro and in vivo. RESULTS Bioinformatics revealed that TMC5 expression was generally higher in tumors than in normal tissues, and its expression was associated with poorer patient survival outcomes. TMC5 expression in HCC tissues and cells was consistent with the results of the bioinformatics analysis. Suppression of TMC5 expression reduced migration, invasion, and proliferation, while also decreasing the expression of epithelial-mesenchymal transition (EMT)-associated molecules in MHCC97-LM3 cells. Conversely, higher TMC5 expression significantly increased cell migration, invasion, proliferation, and EMT in MHCC97 L cells. TMC5 knockdown significantly decreased both the formation and spread of nodules in liver tissue, whereas TMC5 overexpression promoted them. CONCLUSION Our study provides compelling evidence that TMC5 is highly expressed in HCC and drives cancer progression through the activation of EMT-mediated invasion. TMC5 could represent a valuable molecular target for the diagnosis and treatment of HCC.