Onion cultivation faces challenges related to nutrient management, impacting growth, yield and quality. Therefore, this study aimed to evaluate the synergistic effects of elemental sulfur and beneficial elementson onion quantitative and qualitative parameters. The experimental design included treatments with three sulfur rates as the main factor (control, 150 and 200 kg fed^-1) and five beneficial elements as the sub-main factor (without  as control, calcium at rate of 500 g Ca-EDTA fed⁻¹, zinc at rate of 500 g Zn-EDTA fed^-1, copper at rate of 500 g Cu-EDTA fed^-1and manganese at rate of 500 g Mn-EDTA fed^-1). Results showed that the highest sulfur rate (200 kg fed^-1) combined with manganese (500 g fed^-1) yielded the best outcomes. This combination significantly enhanced nutrient availability, photosynthetic efficiency, and overall plant health, leading to superior growth parameters and higher concentrations of photosynthetic pigments and essential chemical constituents in the onion bulbs. Furthermore, the application of sulfur and microelements (copper and zinc in particular) also exhibited substantial improvements in yield and bulb quality. The study concluded that the integrated use of elemental sulfur and microelements is crucial for optimizing onion production. These findings underscore the importance of balanced nutrient management in achieving robust growth and high-quality onion produce, offering a practical solution to the nutrient management challenges in onion cultivation.