<p>The global rubber industry heavily relies on carbon black as a reinforcing filler, which contributes significantly to CO₂ emissions and environmental impact. This study explores the potential of using pyrolytic char derived from raw sewage sludge as an alternative, environmentally friendly filler for styrene-butadiene rubber (SBR). Sewage sludge, rich in organic content, was pyrolysed under various conditions in a laboratory-scale rotary furnace. Response Surface Methodology (RSM) was employed to optimize the pyrolysis parameters, with key factors identified as temperature, heating rate, and holding time. The optimal pyrolysis conditions were determined to be 600&#xa0;°C, a heating rate of 10&#xa0;°C/min, and a holding time of 90&#xa0;min. The resultant sludge char filler demonstrated a surface area of 160 m²/g and a tensile modulus at 100% elongation of 1.65&#xa0;MPa, which outperformed commercial carbon blacks. When incorporated into the rubber matrix, the sludge char exhibited reinforcing properties comparable to those of carbon black, suggesting its viability as a sustainable alternative. However, further optimization of post-production processing and formulation is needed to improve filler-rubber interactions for enhanced performance. This study provides a promising pathway for replacing carbon black with sustainable materials in rubber manufacturing.</p> Graphical Abstract <p></p>