Despite new therapies, breast cancer continues to be the second leading cause of cancer mortality in women a consequence of recurrence and metastasis. In recent years, a population of cancer cells has been identified, called cancer stem cells (CSCs) with self-renewal capacity, proposed to underlie tumor recurrence and metastasis. We previously showed that the adipose tissue cytokine LEPTIN, increased in obesity, promotes the survival of CSCs in vivo. Here, we tested the hypothesis that the Leptin Receptor (LEPR), expressed in mammary cancer cells, is necessary for maintaining CSC-like and metastatic properties. We silenced LEPR via shRNA lentivirus transduction and determined that expression of stem cell self-renewal transcription factors NANOG, SOX2, and OCT4 are inhibited. LEPR-NANOG signaling pathway is conserved between species because we can rescue NANOG expression in human LEPR-silenced cells with the mouse LepR. Using a NANOG promoter GFP reporter, we showed that LEPR is enriched in NANOG promoter active (GFP+) cells. Using lineage tracing, we showed that the GFP+ cells exhibit symmetric and asymmetric division and cell death. LEPR silenced MDA-MB-231 cells exhibit a mesenchymal to epithelial transition morphologically, increased E-CADHERIN and decreased VIMENTIN expression compared to control cells. Finally, LEPR silenced cells exhibit reduced cell proliferation, self-renewal in tumorsphere assays, and tumor outgrowth in xenotransplant studies. Given the emergence of NANOG as a pro-carcinogenic protein in multiple cancers, these studies suggest that inhibition of LEPR may be a promising therapeutic approach to inhibit NANOG and thereby neutralize CSC functions.