<p>Stone Matrix Asphalt (SMA) is designed with a high-quality aggregate framework that delivers long-lasting performance, offering excellent resistance to pavement distresses and efficient drainage. As a result, SMA enhances pavement durability and promotes road safety, making it a preferred choice for heavy-loaded pavement. However, the high binder content and the need for superior quality aggregates make SMA production expensive, prompting researchers to explore strategies for reducing its cost. This study examined the viability of fully substituting coarse and fine natural aggregates in SMA with steel slag aggregate and jarosite to improve sustainability. The novelty of this study lies in the complete simultaneous incorporation of both waste materials to evaluate their synergistic effects on SMA properties. A series of asphalt mixtures were produced by substituting fine aggregate with varying proportions of jarosite (0%, 25%, 50%, 75%, and 100%) while fully replacing the coarse aggregate with steel slag. All prepared asphalt mixtures were evaluated for engineering performance using skid resistance, resilient modulus, wheel tracking, cracking tolerance index, indirect tensile strength, and Cantabro tests. Asphalt mix fabricated with 100% fine jarosite and coarse steel slag exhibited higher 228% rut resistance, 75% dry skid resistance, 240% fracture resistance, 168% unaged ravelling resistance and 34% dry cracking resistance than conventional mix. Which is attributed to the low VMA and high stiffness of 100% fine jarosite mixes. The inclusion of steel slag and 100% jarosite reduced the Global Warming Potential (GWP) of the asphalt mixes by 34% compared to the control mix.</p>