RNA-binding protein 24 (RBM24) has been shown to play tumor-suppressive functions in various types of cancer. The present study aimed to investigate the role of RBM24 in liver cancers and its downstream mechanisms. The present study demonstrated that RBM24 functioned as a tumor suppressor in liver cancer cells, and inhibited nuclear translocation of β-catenin and tumor protein 63 expression by immunocytochemistry. In addition, RBM24 could suppress sphere formation in a multicellular tumor spheroid model of liver cancer cells. In conclusion, it is hypothesized that RBM24 is a tumor suppressor of liver cancer cells, which could be a potential novel therapeutic target for treatment of patients with liver cancer.