MicroRNAs are a class of non-coding short-stranded RNAs with important biological roles as post-transcriptional regulators of gene expression, involved in a variety of biological processes, such as cell growth, apoptosis, and angiogenesis. miR-23b, a well-studied miRNA, is aberrantly expressed in a variety of cancers. In this paper, we used the literature review method to sort out the biological roles and regulation of miR-23b in different types of cancers, including digestive system cancers, reproductive system cancers, head and neck cancers, genitourinary system cancers, and lung cancers. The data show that miR-23b can target both oncogenes and tumor suppressors, and its expression regulation in different types of cancers shows heterogeneity, which mainly acts through affecting signaling pathways, such as Wnt/β-catenin for tumorigenesis, and apoptotic proteins, such as BCL2 or oncogenes. The expression of miR-23b is closely related to the overall survival rate, disease-free survival rate, and prognosis in many cancers. Meanwhile, various in vivo and ex vivo studies have shown that miR-23b is a potential therapeutic target for cancer. It is important to understand the relationship between miR-23b and cancer development. miR-23b has the potential to serve as a clinically relevant molecular biomarker for cancer prognosis/diagnosis as well as a potential therapeutic target.