It is becoming increasingly appreciated that biophysical influences on tissues are at least as important as biochemical influences in regulating normal development and homeostasis. Furthermore, diseases of aberrant tissue homeostasis such as cancers are driven by the abnormal biophysics of cancerous tissues. The mammary gland, a mechanoresponsive tissue, is exquisitely sensitive to changes in its mechanical microenvironment. Forces playan important role in normal mammary development, lactation, and involution, as well as in mammary neoplasia. As such the mechanical influences on normal tissue homeostasis and neoplasia are easilystudied in this tissue. Here, we discuss the role of mechanical forces in these developmental and homeostatic processes and highlight insights gained from new findings in the field of mammary mechanobiology. We also discuss the potential for harnessing these insights into novel anticancer therapy approaches that halt tumor progression, with opportunities to revolutionize cancer care and outcomes for patients.