This study investigates the impact of foliar application of potassium sulfate and selected amino acids (tryptophan, methionine, and cystine) on the yield and quality attributes of ‘Superior’ grapevines in Minia Governorate, Egypt, across the 2023 and 2024 growing seasons. Thirty uniform grapevines were subjected to ten treatments with 3 replicates in Complete Randomize Bloch Design, including varying concentrations (0.05, 0.1 and 0.2%) each of potassium sulfate, amino acids, and their combinations, applied thrice during growth stages. Results demonstrated that both potassium sulfate and amino acid treatments significantly enhanced cluster and berry characteristics, yield per vine, and berry quality compared to untreated control. The combination of 0.1% potassium sulfate and amino acids, applied three times during the season, was identified as the most cost-effective treatment, resulting in substantial increases in cluster number, berry size, weight, juice percentage, total soluble solids, and reducing sugar content, while reducing berry acidity and shot berry percentage. Higher concentrations (0.2%) yielded similar improvements, but without significant differences from the 0.1% treatment. The findings underscore the synergistic benefits of integrating potassium sulfate and amino acids as foliar sprays to optimize grapevine productivity and fruit quality, offering a practical strategy for sustainable viticulture under semi-arid Egyptian conditions.