Context: Awareness is important in combating breast cancer, as early detection (through mammograms) and prompt treatment offer the greatest chance of long-term survival. Aims: The aim of this study was to assess public knowledge of breast cancer (signs, symptoms, and risk factors) and awareness of screening programs; and compare it among men and women. Materials and Methods: A cross-sectional study was conducted among male and female residents of five of the geographic regions of Saudi Arabia from February 2015 to May 2015. Information was collected using a questionnaire, and included sociodemographic data, general knowledge about breast cancer, and awareness of screening programs. Chi-square d test was used to compare the binary knowledge variables (correct/incorrect) between men and women. Logistic regression was utilized to assess predictors of breast cancer knowledge. Results: A total of 9691 men and 31,022 women were surveyed. Women had better knowledge regarding breast cancer symptoms than men, except for breast cancer being related to death. Men and women had similar knowledge of breast cancer risk factors; however, more women correctly identified family history (68%), large breast size (46%) as increasing risk, and breastfeeding (60%) as reducing the risk of breast cancer compared to men (56%, 32%, and 47%, respectively). Older age and higher education were related with high breast cancer knowledge, and it was more pronounced among men. Employment was a predictor for better knowledge among women. Participants with no history of breast cancer were less likely to have good breast cancer knowledge compared with those with a family history, (OR: 0.5, 95% CI: 0.5-0.6) and (OR: 0.6, 95% CI: 0.5-0.6) among men and women, respectively. More women (24%) than men (19%) knew of breast cancer screening programs, although the awareness was low in both genders. Conclusion: Awareness campaigns in Saudi Arabia, especially those aimed at men, remain critical to increase knowledge and change behavior toward early detection of breast cancer.