The Forkhead box C1 (FOXC1) transcription factor is involved in normal embryonic development and regulates the development and function of many organs. Most recently, a large body of literature has shown that FOXC1 plays a critical role in tumor development and metastasis. Clinical studies have demonstrated that elevated FOXC1 expression is associated with poor prognosis in many cancer subtypes, such as basal-like breast cancer (BLBC). FOXC1 is highly and specifically expressed in BLBC as opposed to other breast cancer subtypes. Its functions in breast cancer have been extensively explored. This review will summarize current knowledge on the function and regulation of FOXC1 in tumor development and progression with a focus on BLBC, as well as the implications of these new findings in cancer diagnosis and treatment.