Evidence indicates that whole-grain food consumption reduces the risk of cardiovascular disease, type-2 diabetes, and some cancers. Increasing whole-grain consumption in developing countries is likely to significantly benefit the health of the population. However, there is very limited information on consumer whole-grain knowledge, attitudes, and behaviors in developing countries. An online cross-sectional survey was conducted among 1000 South African consumers with sufficient income to make food purchase choices and who were generally representative in terms of gender, age, and ethnicity. Most respondents (64%) were confident of their whole-grain knowledge. However, 60% of all participants selected incorrect definitions of whole grains. Whilst most correctly identified common cereals as whole grains, at most 50% of participants correctly identified common whole-grain foods. Also, whilst most (67%) thought that they were consuming enough whole grains, the majority (62%) underestimated the recommended level of consumption. Furthermore, respondent knowledge regarding whole-grain food attributes and the health benefits of whole-grain consumption was generally poor. Clearly, consumer-focused strategies are needed in developing countries to increase whole-grain food consumption to help the broader population achieve a healthy and sustainable diet. Actions proposed include: simple-to-understand information on whole-grain content relative to recommendations on food product labels, the provision of whole-grain foods in school nutrition schemes, and coordinated social and behavior change communication initiatives.