This chapter explores the nutritional, health, and cultural significance of cereal-based ethnic fermented foods. Such foods, integral to cultural identity, face challenges from globalization and climate change, as urban diets increasingly favor fast foods. Nonetheless, fermented foods remain valued for their health benefits, such as improved nutrient absorption and longevity support. Fermentation, often achieved with minimal resources, employs microorganisms influenced by pH, salt, and temperature, resulting in varied flavors and nutrient profiles. Commonly fermented cereals like maize, sorghum, and millet serve as weaning foods and staples, offering extended shelf life, enhanced flavors, and health benefits. Lactic acid bacteria (LAB), vital to these processes, promote digestive health and may reduce allergies. High in fiber and beta-glucan, these foods benefit heart health and serve as functional foods, lowering anti-nutritional factors to improve nutrient absorption. They also contain prebiotics and probiotics, which support gut health and metabolic wellness. Documenting traditional fermentation practices can help standardize production, ensuring quality while preserving cultural heritage and promoting public health. Some of the common cereal-based fermented food products such as idli, dosa, dhokla, unniyappam and beverages like angoori, O, and Sira-O are discussed in this chapter.