This study investigated the effect of red ginseng extract (RGE) on the physicochemical properties, sensory test, and antioxidant activity of milk. The milk samples with RGE added at 0.5, 1, 1.5, and 2% were analyzed during storage at 4°C. The physicochemical properties included composition of milk, pH, titratable acidity, and color. The antioxidant activity of milk samples was determined using the 2,2-diphenyl-1-picrylhydrazyl method, β-carotene bleaching assay, and ferric thiocyanate assay. An increase in the amount of RGE in milk resulted in an increase of lactose and total solids content, titratable acidity, and a* and b* values, whereas fat and protein contents remained unchanged. Also, pH and L* value decreased. The antioxidant activity of milk samples supplemented with RGE was higher than that of the control sample. Sensory evaluation was performed using a quantitative descriptive analysis. Two types of samples were used: (1) sterilized milk fortified with RGE (0.5, 1, 1.5, and 2%) and (2) 2% RGE, 2% RGE with oligosaccharide, and 2% RGE with oligosaccharide and cyclodextrin. The addition of oligosaccharide and cyclodextrin could effect an increase of sweetness, a decrease of bitterness and flavor of RGE, and aftertaste. Therefore, milk supplemented with RGE could be useful as a functional food.