<p>Sulfur waste has recently been considered as a sustainable alternative to traditional calcium carbonate mineral fillers in hot mix asphalt (HMA). This study evaluates the effects of incorporating polylactic acid (PLA) polymer at different ratios (0.5%, 1.0%, 1.5%, and 2% by weight of asphalt) into HMA mixtures containing either sulfur waste or calcium carbonate as fillers Both unmodified and PLA-modified asphalt binders were evaluated for homogeneity and physical properties. Eight distinct mixture types underwent performance assessments, including rutting resistance (Kim test), cracking resistance, fracture energy, flexibility index, and J-integral (fatigue parameter), using the Kim test and semi-circular bending (SCB) method. The main findings were: (i) For unmodified HMA mixtures, the Kim (rutting) resistance values were nearly identical: 4.74&#xa0;MPa for calcium carbonate and 4.73&#xa0;MPa for sulfur waste. (ii) When 1.0% PLA was added, the deformation strength increased to 5.92&#xa0;MPa for calcium carbonate and 5.45&#xa0;MPa for sulfur waste, representing improvements of 25% and 15%, respectively, compared to the unmodified mixtures. (iii) In the SCB test, SCB test results showed that PLA-modified mixtures, with either filler type, had notably better cracking resistance and flexibility than unmodified mixtures, especially at 1.0% PLA content. (iv) PLA modification at 1.0% led to a significant enhancement in rutting, cracking, and fatigue resistance for both filler types. Sulfur waste proved to be a viable, sustainable mineral filler, achieving comparable or improved performance to calcium carbonate, especially when combined with PLA. These results indicated that using sulfur waste as a filler, particularly with PLA modification, can improve the mechanical performance and sustainability of asphalt mixtures, providing a promising approach for eco-friendly pavement solutions.</p>