Background and objectives Despite positive agronomic and nutritional characteristics, millets are underutilized for food use in the Western Hemisphere. Little is known about the end‐use quality characteristics of available proso millet varieties, nor their adaptation to and performance in double crop situations in northern states. Therefore, the objective of this work was to evaluate several proso millet varieties grown in two locations for composition as well as attributes that influence processing, nutritional quality, and physiological benefits. Findings Proso millet varieties were similar in chemical composition (total starch, protein, lipid, dietary fiber, and ash content), but were notably different in amylose content of starch (ranging from 7.8% to 34.8% amylose). Lower amylose content resulted in lower peak temperature, final viscosity, and setback. Varieties also differed in carotenoids and hydroxycinnamic acids content as well as in antioxidant activity. Slowly digestible starch represented the major starch fraction in cooked flour, and protein digestibility was reduced to less than 50% after cooking. Conclusions Overall, growing location did not have a great impact on chemical and functional characteristic, while some varietal differences were noted. Significance and novelty The basic information provided regarding composition and functionality differences among various millet varieties will aid in the identification of potential food applications.