In this study, three formulations were prepared with different whey and mango proportions (sample-1 = 60:20 mL, sample-2 = 65:15 mL, and sample-3 = 70:10 mL). Over a 25-day storage period, the prepared beverage samples exhibited significant changes 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%). Sedimentation rate was negligible at 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. Coliform count was below the detection limit (<1). Overall sensory evaluation indicated that the whey beverage with higher mango juice content achieved an acceptable quality during processing. These findings suggest the potential of whey in developing beverages when combined with fruits and vegetables.