Breast cancer is the most common cancer diagnosis for women in the USA and ranks second in cancer-related deaths. Disproportionately higher breast cancer rates can be found in rural and Appalachian regions due to several social drivers of health, including poverty, access to healthcare, and lack of culturally sensitive health education. Amish and Mennonite communities, religious groups with distinct cultural practices and beliefs, experience lower mammography screening and higher breast cancer mortality rates (among Amish women). This study focuses on knowledge about breast cancer and causes of cancer among Amish and Mennonite women. A total of 473 women participated in the study at 26 separate women's health clinics throughout Ohio, consisting of 348 Amish and 121 Mennonite women, the largest study conducted on breast cancer knowledge spanning dozens of communities. Statistically significant differences were found in total knowledge scores between Amish and Mennonite women (rpb = .178, n = 466, p = .007), with Amish women having lower scores and stronger beliefs in myths associated with breast cancer cause and symptoms (χ(1) = 7.558, p = .006). Both groups often provided scientifically accurate descriptions of cancer etiology. The majority of participants underestimated breast cancer risk, highlighting the need for culturally appropriate health education programs that consider numeracy and health literacy. By implementing targeted interventions and fostering partnerships with community stakeholders using a multifaceted approach that incorporates cultural sensitivity, community engagement, and collaboration, significant progress can be made towards reducing breast cancer disparities and improving health outcomes.