Here, we characterized the changes in fruit quality and biochemical parameters in four Myanmar mango cultivars from ripening stage 1 to 4 at ambient temperature. Total soluble solids, total sugars, and reducing and non-reducing sugar content increased, whereas titratable acidity decreased with increasing storage time in all cultivars. ‘Sein Ta Lone’ showed the highest consumer acceptability, with maximum sensory quality scores owing to its unique characteristics. ‘Hin Thar’ and ‘Ma Chit Su’ also had better quality and sensory attributes than ‘Yin Kwae’. Sugar/acid ratios in all cultivars ranged from 23 to 50, the standard sugar/acid ratios in high-quality mango fruits. The total phenolic content (TPC) and antioxidant activity among cultivars ranged from 8.20 to 14.96 mg gallic acid equivalents and 19.52 to 26.79 mg vitamin C equivalents antioxidant capacity, respectively, per 100 g of fruit extract throughout the storage. ‘Hin Thar’ was the richest in phytochemical compounds. A significant positive correlation was found between total phenolic activity and 2,2-diphenyl-1-picryl-hydrazyl free radical scavenging activity of fruits, showing that TPC exhibited linear relationships with the antioxidant activities of each mango variety during the different stages of ripening.