Obesity and environmental toxins are risk factors for breast cancer, however there is limited knowledge on how these risk factors interact to promote breast cancer. Acrylamide, a probable carcinogen and obesogen, is a biproduct in foods prevalent in the obesity-inducing Western diet. Acrylamide is metabolized by cytochrome P450 2E1 (CYP2E1) to the genotoxic epoxide, glycidamide, and is associated with increased risk for breast cancer. To investigate how acrylamide and obesity interact to increase breast cancer risk, female mice were fed a low-fat (LFD) or high-fat diet (HFD) and 0.7mM acrylamide-supplemented water or control water. While HFD significantly enhanced weight gain in mice, the addition of acrylamide did not significantly alter body weights compared to respective controls. Mammary epithelial cells from obese, acrylamide-treated mice had increased DNA strand breaks and oxidative DNA damage compared to all other groups. In vitro, glycidamide-treated COMMA-D cells showed significantly increased DNA strand breaks while acrylamide-treated cells demonstrated significantly higher levels of intracellular reactive oxygen species. Knockdown of CYP2E1 rescued the acrylamide-induced oxidative stress. These studies suggest that long-term acrylamide exposure through foods common in the Western diet may enhance DNA damage and CYP2E1-induced generation of oxidative stress in mammary epithelial cells, potentially enhancing obesity-induced breast cancer risk.