Increasing the added value of multi-component municipal solid waste (MSW) through thermochemical conversion provides dual benefits: reducing urban waste accumulation and generating renewable energy. In rapidly growing urban areas with increasing waste volumes, the urgency of converting waste into fuel is necessary. This study optimises pyrolysis process parameters to improve the yield and quality of liquid fuel derived from MSW. Using response surface methodology (RSM) and desirability function technique (DFT) allows optimal parameter prediction and minimises experimental costs. Experiments were conducted using a two-stage fixed-bed pyrolysis reactor with natural dolomite as a catalyst. Central composite design (CCD) was applied to ensure statistical reliability. The results show a nonlinear effect of temperature on the liquid and provide a maximum yield of 30.8 wt. %, while time plays a greater role in increasing the energy density to 9978 kcal/kg. The model showed a high coefficient of determination (R2 = 0.9571) with optimal parameters identified at a temperature of 488.3 °C and a time of 202.1 minutes, and produced a liquid fuel with physicochemical characteristics comparable to commercial diesel. This study introduces a strategic pathway to accelerate the valorisation of MSW into high-quality fuels, which strengthens sustainable MSW management initiatives.