Lectin galactoside-binding soluble 3-binding protein (LGALS3BP) is associated with cancer metastasis and is a promising prognostic marker in neoplasms. In hepatocellular carcinoma (HCC), the prognostic impact and pro-metastatic function of LGALS3BP remain unclear. This study evaluated the endogenous LGALS3BP expression in HCC tissue and its association with prognosis. LGALS3BP protein levels were significantly elevated in clinical HCC tissues and cell lines. Increased LGALS3BP expression was closely associated with disease progression in HCC patients, and they also exhibited an unfavorable prognosis. Furthermore, the knockdown of LGALS3BP inhibited the growth, migration, and invasion of HCC cells in vitro. In mice xenografts, silencing LGALS3BP significantly inhibited tumor cell growth in vivo. Mechanically, upon LGALS3BP depletion, the tumor-suppressive function was dependent on inactivating Phosphatidylinositol 3-kinase (PI3K)/V-akt murine thymoma viral oncogene homolog (AKT) signaling pathway. Collectively, these findings suggest that LGALS3BP employs a pro-tumorigenic function in HCC and may be a promising HCC prognostic marker.