Sex-determining region Y-box protein 2 (SOX2) is an embryo transcription factor located on chromosome 3q26.3-q27. It plays an important role in the maintenance of differentiation and self-renewal of pluripotent stem cells. Studies have shown that SOX2 is associated with multiple cancers and is overexpressed in many different phenotypes of breast cancer. To study the relationship between SOX2 and clinicopathological parameters of breast cancer patients, we found that the expression of SOX2 was closely related to the increase in tumor size, histological grade, lymph node metastasis, and high invasiveness. Therefore, studies on the role of SOX2 in breast cancer may provide effective biomarkers and potential therapeutic targets for the diagnosis and treatment of breast cancer. This article will discuss the role of SOX2 in breast cancer, including its occurrence, invasion and metastasis, diagnosis and treatment, relapse, resistance, and prognosis.