The purpose of this study is to optimise biodiesel production from palm stearin using the Box-Behnken design in response surface methodology (RSM) for three key process parameters: Methanol volume, catalyst concentration and reaction time. The methanol (A) was fixed at three levels: -1, 0, and +1, corresponding to 200, 225 and 250 mL, respectively; the catalyst (B) concentration was varied between 8, 10, and 12 g; and the reaction time (C) ranged from 45-90 min. The experiments were conducted and analysed using Design Expert software (version 13) to maximise biodiesel yield. The highest yield of palm stearin methyl ester (910 mL, 89.25% yield) was achieved with 225 mL methanol, 10 g catalyst and a reaction time of 60 min. The optimised model predicted a yield of 913.4 mL, demonstrating strong agreement with experimental results. This study is significant in promoting more sustainable biodiesel production by improving efficiency and reducing both operational costs and environmental impact. By optimising process parameters, this work addresses the need for cost-effective renewable fuel alternatives, contributing to the long-term commercial viability of biodiesel in the energy market.