Declining intake of polyphenol-rich foods has contributed to the rising global diet-related health problems (1). Reformulation of staple cereal-based foods to include polyphenol-rich grains has the potential to improve dietary intake without compromising sensory appeal. Coloured grains, including black wheat (Triticum aestivum L), red sorghum (Sorghum bicolor (L.) Moench) and brown teff (Eragrostis tef (Zucc.) Trotter), are rich in polyphenols, fibre and micronutrients (2,3,4) and are often deficient in population health, making them a promising functional ingredient for improving bread quality. This study aimed to evaluate the nutritional enhancement, physicochemical properties and consumer acceptance of functional breads reformulated with underutilised polyphenol-rich coloured grains. Half of the white bread flour was reformulated with either black wheat, red sorghum or brown teff. Dough rheology and RVA were analysed using TA.XT plus Texture Analyser and Perten Rapid Visco Analyser 4500, respectively; nutrient composition was analysed using Foodworks; and consumer sensory acceptance was assessed using a 9-point hedonic scale and 7-point purchasing scores using 40 healthy adult participants. All data were statistically analysed using Welch’s ANOVA test. Compared to white bread, black wheat bread contained 10.5 mg/100 g more total polyphenols, 1.7 mg/100 g more anthocyanins and higher fibre (+29%; p < 0.0001), calcium (+45%; p < 0.0001) and iron (+4.5-fold; p < 0.0001), with lower total energy (-11%; p < 0.0001). Similarly, red sorghum bread contained 23.6 mg/100 g more total polyphenols, 0.6 mg/100 g more anthocyanins and higher protein (+14%; p < 0.0001), calcium (+17%; p < 0.0001) and iron (+8.9-fold; p < 0.0001) but lower fibre (-8.6%; p < 0.0001) and total energy (-5%; p = 0.001). Brown teff bread is considered the most nutritious, with 47.3 mg/100 g more total polyphenols, 0.4 mg/100 g more anthocyanins and higher protein (+26%; p < 0.0001), fibre (+19%; p < 0.0001) and 2.5-fold increase each in calcium and iron content (p < 0.0001), without a difference in total energy (95% CI: 93.8, 141.5; p = 0.95). All newly formulated functional breads contained lower total carbohydrate (7-12%; p < 0.001), sugar (22-24%; p < 0.001), and starch content (6-16%; p < 0.001), with no differences in most vitamins, except having 50% lower folate due to mandatory fortification of white bread flour, without compromising sensory appeal. Substituting half of the white flour with underutilised coloured grains, particularly black wheat, red sorghum, or brown teff flour, substantially improved their nutritional profiles, particularly in total polyphenols, carbohydrates, protein, fibre, calcium, iron, potassium, magnesium, phosphorus and zinc, thereby substantiating their potential as promising, sustainable, nutrient-dense options. Further research into consumer acceptance of these polyphenol-rich functional breads and their effects on metabolic biomarkers is underway to support purchasing frequency and their implications for improving population health.