The present study was aimed at developing whey-mango-based mixed beverages and characterizing their physicochemical properties. Three different formulations were prepared by varying proportions of whey and mango (sample-1 = 60:20 mL, sample-2 = 65:15 mL, and sample-3 = 70:10 mL). Prepared beverage samples during 25 days of storage revealed a significant increase in acidity (0.27 ± 0.02–0.64 ± 0.03%), TSS (17.15 ± 0.01–18.20 ± 0.01 °Brix); reducing sugars (3.01 ± 0.01–3.67 ± 0.01%); moisture (74.50 ± 0.02–87.02 ± 0.03%); protein (5.67 ± 0.02–7.58 ± 0.01%); fat (0.97 ± 0.01–1.39 ± 0.04%); and carbohydrate (18.01 ± 0.02–3.45 ± 0.02%). The sedimentation rate was only 1%. The total plate count for the prepared samples ranged from 3.32 ± 0.08 to 3.49 ± 0.15 log CFU/mL while yeast and mold counts varied between 0.48 ± 0.01 to 1.85 ± 0.11 Log CFU/mL. The coliform count was below the detection limit (<1). The overall sensory score revealed that the whey beverage with more mango juice could attain acceptable quality upon processing. Based on the findings, it may be concluded that whey can be utilized with fruits and vegetables to develop whey-based beverages.