<p>This study investigates the optimization of wool dyeing using Papaver rhoeas extract as a natural dye, with a focus on improving color strength (<i>K</i>/<i>S</i> value). Response Surface Methodology (RSM) with a Central Composite Design (CCD) was applied to evaluate the effects of key dyeing parameters, dye concentration, temperature, dyeing time, and pH, on <i>K</i>/<i>S</i>. The developed quadratic model exhibited strong statistical significance (<i>R</i>² = 0.92, <i>F</i>-value = 93.28, <i>p</i> &lt; 0.0001), confirming the reliability of the fitted response surface. Optimal conditions were identified as 108.17% dye concentration, 77.44°C temperature, 117.81 min dyeing time, and pH 3.02, resulting in a high predicted <i>K</i>/<i>S</i> value of 4.00. The model predictions were validated by experimental trials, showing minimal deviation. In addition, the impact of mordanting methods (pre-, meta-, and post-mordanting) and different mordant types (natural and metallic) on colorimetric and fastness properties was investigated. Post-mordanting using natural mordants, especially red onion peel, achieved the highest <i>K</i>/<i>S</i> (9.73) and improved both wash and light fastness. Overall, this research demonstrates the value of RSM in optimizing natural dyeing processes, improving reproducibility, and reducing experimental effort. It supports the development of eco-friendly textile dyeing using plant-based materials.</p> Graphical abstract <p></p>