Barnyard Millet, a gluten-free grain, is recognized for its abundant bioactive polyphenols and offers various health benefits, including high B vitamins, magnesium, and other minerals. It has been associated with reducing weight, BMI, and high blood pressure, and research validates its preventive effects against obesity and diabetes. The multipin atmospheric cold plasma technique was utilized to study its effect on the bioactive and functional properties of the Barnyard millet flour. Barnyard millet grains were dehulled and ground to pass with a 100-micron sieve and further treated with atmospheric cold plasma at various time-temperature combinations. Overall, all properties of the control showed changes compared to the 30:30 treatment. SC and AOA decreased, while water solubility, viscosity, TPC, and TFC increased, with the most changes observed at 30:30 treatment. Tannin and Phytic acid, however, decreased across all treatment times, with the highest decrease at 30:20. The impact of Cold Plasma on Barnyard Millet flour has shown significant modifications in both bioactive and functional properties. The 30:30 treatment, in particular, demonstrated significant improvements, including increased water solubility and enhanced emulsifying and foaming capacity. Cold plasma-treated Barnyard Millet flour offers versatile applications, improving nutritional and functional qualities in baked goods, functional foods, and gluten-free products.