PURPOSE: Clonal hematopoiesis (CH) has been associated with a variety of adverse outcomes, most notably hematologic malignancy and ischemic cardiovascular disease. A series of recent studies also suggest that CH may play a role in the outcomes of patients with solid tumors, including breast cancer. Here, we review the clinical and biological data that underlie potential connections between CH, inflammation, and breast cancer, with a focus on the prevalence and impact of clonal hematopoiesis of indeterminate potential in patients with breast cancer. METHODS: We summarize data from multiple studies, including a series of cohorts of patients with breast cancer, to assess the prevalence of CH, the relationship between CH and exposure to cytotoxic therapy, and the correlation between CH and breast cancer-specific outcomes. RESULTS: Our findings indicate that CH is prevalent among patients with breast cancer, particularly those treated with cytotoxic therapies. However, there are no definitive data to support an association between the presence of CH and breast cancer-specific outcomes. CONCLUSION: Current data do not support routine CH testing in patients with breast cancer, nor should the presence of CH influence decisions regarding breast cancer therapy in most patients. However, larger, long-term studies are necessary to further define the implications of CH in patients with breast cancer and guide clinical decision making.