Sesame (Sesamum indicum L.), a vital oilseed crop valued for its oil quality and drought tolerance, faces yield and quality challenges in arid regions like southern Iran, where farmers contend with water scarcity and high fertilizer costs. A two-year field study (2023-2024) in semi-arid Esfahan province evaluated the synergistic effects of phosphorus (P), Funneliformis mosseae (AMF), and humic acid on sesame cv. Dashtestan under drought stress, hypothesizing that reduced P with AMF and humic acid would enhance yield and oil quality via improved nutrient uptake compared to conventional treatments. Using a split-plot design with three replications, treatments comprised three irrigation regimes (I1: 40% soil moisture depletion, I2: 60%, I3: 80%) and seven fertilizer treatments (F1: control, F2: 100% P, F3: AMF, F4: humic acid, F5: 50% P + AMF, F6: 50% P + humic acid, F7: 50% P + AMF + humic acid). Combined treatments (F5, F6, F7) outperformed F1-F4, validating the hypothesized improvements with F5 achieving a seed yield increase with 62% (exceeding the 30-50% range) and oil yield with 85.5% (aligning with or surpassing expected synergies). These treatments enhanced oil quality, improving linoleic acid (up to 43.5%), oleic acid (41.2%), palmitic acid (9.0%), stearic acid (5.8%), lignan content (3600 mg kg-1, +80%), and antioxidant capacity (28.5 mu mol L-1, +185%) under drought. Integrated nutrient management with reduced P, AMF, and humic acid offers a sustainable strategy for optimizing sesame yield and oil quality in water-scarce regions, reducing chemical inputs while boosting economic value for farmers.