With the increasing population and rising demand from new manufacturing industries, the amount of waste generated continues to grow, resulting in vast quantities of waste materials being disposed of in landfills each year. During the production of aluminum, the extraction of alumina from bauxite ore produces a by-product known as red mud. Globally, red mud production is considerable, with approximately 150 million tons generated annually. In Saudi Arabia, over 50% of the waste from aluminum production is red mud, amounting to millions of tons. Disposing of red mud has long been a challenge due to traditional storage methods, which have occasionally led to environmental pollution and accidents. To address this, researchers and engineers have been investigating alternative uses for red mud to reduce its environmental impact. One promising application is in the road construction industry. This study evaluates the use of industrial waste, specifically red mud, as a substitute filler in asphalt mixtures, utilizing the Marshall mix design method. Laboratory tests were conducted with varying percentages of red mud (0%, 25%, 50%, 70%, and 100%) replacing conventional filler to assess the mixtures’ stability, flow, and volumetric properties. The results indicate that red mud can effectively replace filler in asphalt mixtures by up to 50% while still meeting the Ministry of Transport and Logistic Services’ design specifications.