The warm climate in the southeastern United States allows for extended grazing seasons; however, there is limited information on the nutritional quality of forage mixtures to sustain pasture-based organic dairy production. A study was conducted to evaluate the nutritional quality of 9 forage mixtures designed for this region. Mixtures of cool-season perennial and annual legumes (red clover, alfalfa, crimson clover), cool-season perennial and annual grasses (tall fescue, orchard-grass, annual rye-grass), warm-season annual grasses (sorghum-X sudan-grass hybrids, crabgrass), and warm-season annual legumes (annual lespedeza, cowpea) were established in a randomized complete block design at the East Tennessee Research and Education Center-Organic Crops Unit. Plots (2 × 10 m, 4 replicas per plot) were harvested twice at the appropriate growth stages. Grab samples were analyzed using near-infrared spectroscopy (Foss-DS2500, Foss America, Eden Prairie, MN) to determine crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), lignin, and in vitro dry matter digestibility for 48 h (IVTDMD48h). Data were analyzed in SAS 9.4 using the GLIMMIX procedure and the model included the fixed effects of forage mixture, replica, time, and their interactions. Data from the first set of harvests indicate that average CP ranged from 8.2 to 15.0%, with greatest concentrations in mixtures that contained legume species (P < 0.01). Concentrations of ADF ranged from 40.2 to 45.2%, with the lowest concentration in monoculture orchard-grass stands. Concentrations of NDF ranged from 54.1 to 67.6%, with the lowest concentrations in mixtures containing red clover (P < 0.01). Lignin content ranged from 4.2 to 8.5%, with the lowest content in red clover stands (P < 0.01). Prediction means of IVTDMD48h ranged from 63.5 to 68.8%, with the greatest digestibility in orchard-grass-red clover mixtures (P < 0.01). Results indicate that mixed grass-legume stands should provide nutrients to enhance organic dairy production in the Southeast. Additional information is needed over multiple seasons in combination with dairy cow responses to mixed stands.