Breast cancer ranks as one of the most prevalent malignancies globally, predominantly affecting the female popula- tion. Notably, the expression of class IIa histone deacetylases (HDACs), particularly histone deacetylase 5 (HDAC5), exhibits significant variation between breast cancer patients and healthy individuals. This differential expression positions HDAC5 as a promising biomarker for breast cancer and potentially other cancer types. Furthermore, HDAC5 has emerged as a credible mo- lecular target for anticancer therapeutics. This review aims to concisely summarize the structural characteristics of HDAC5, its contributory role in the pathogenesis of breast cancer, and the therapeutic potential of HDAC5 inhibitors. We will discuss the feasibility of detecting HDACs, designing histonedeacetylase inhibitors (HDACi), and identifying effective drug targets in con- junction with HDACi. Our goal is to offer strategic insights for advancing breast cancer treatment, focusing on the application of HDACi in managing breast cancer tumors.