The Hedgehog (Hh) signaling pathway plays a key role in a variety of processes, such as embryogenesis and maintenance of adult tissue homeostasis. It is also becoming increasingly clear that this pathway can have a crucial role in tumorigenesis. Most recently, the Hh signaling pathway has been implicated in the development and maintenance of breast cancer. Here we review Hh signaling, advances in small molecule and antibody-based inhibitors targeting the Hh pathway, and dysregulation of the Hh signaling pathway in breast cancer.