Millet flours are increasingly used in traditional and value-added foods, but their reported proximate composition varies with genotype, dehulling, milling, processing, sample basis and analytical method. This review compared the proximate composition of ragi (finger millet), jowar (sorghum), foxtail millet and barnyard millet flours using published secondary data. Literature was identified through PubMed, ScienceDirect, Google Scholar, Wiley Online Library and Oxford Academic and was supplemented by authoritative food-composition and regulatory sources. Studies were selected when millet identity and proximate values were clearly reported, and direct comparison was restricted to flour observations reported on an as-is (fresh-weight) basis. Ragi control flours showed 10.51–10.60 g/100 g moisture, 10.75–10.80 g/100 g protein and 1.70–1.72 g/100 g fat. Jowar flour contained 12.03 g/100 g protein and 3.56 g/100 g fat, while foxtail millet flour contained 11.65 g/100 g protein, 3.48 g/100 g fat and 2.21 g/100 g crude fiber. Barnyard millet flour contained 10.50 g/100 g protein, 3.60 g/100 g fat and the highest ash content (3.40 g/100 g); its crude fiber was not reported. Mean ± SD could be calculated only for the two comparable ragi observations. The selected flours differed measurably in composition, and part of this difference was attributable to sample preparation and analytical method. Standardized flour preparation, reporting basis and analytical procedures are needed before values from different studies can be pooled as species-level estimates.