The aim of this study was to assess the effects of low/high quality legume residue addition on the chemical composition and quality of maize grain. The experiment followed a randomized block design with a 6 × 2 factorial arrangement, and four repetitions. The plots comprised different combinations of leguminous plants (LC, LA, LG, GC, and GA) and one control group, whereas the subplots were simultaneously cultivated with QPM BR 473 and hybrid AG 7088 maize cultivars. Lipid, protein, starch, fiber, mineral residue, mineral, sugar, carbohydrate, and amino acid levels were analyzed. Legume-biomass treatments applied to the two cultivars affected all mineral contents in the grains, except for calcium. In hybrid cultivar, the legume-biomass treatment provided increased mineral, reducing sugar, and fiber contents. The LG, GA, and GC treatments showed higher protein content during cultivation than the control in both cultivars. In the QPM cultivar, throughout the two cultivations, each one of the legume-based treatments the highest contents for amino acids when compared to the control. The different effects of legume residue-based treatments on different cultivars are associated with efficient nitrogen deposition in the soil and with nitrogen accumulation in plants. Each of the chemical parameters analyzed in the maize cultivars displayed different levels when subjected to treatments using legumebiomass. Legume-biomass helped improve the physicochemical profile of maize grains in the assessed cultivars, including QPM.