The primary aim of this research article is to examine the potential application of waste marble powder as a means to enhance the stability of soils with high clay content. The present study investigates the historical and extensive utilization of chemical additives in soil stabilization methods for the purpose of ground improvement. The experimental procedure entails manipulating the proportion of marble powder within the range of 0–10%. The present study investigated a range of factors, including index properties, i.e., particle size distribution, liquid limit (LL), plastic limit (PL), Atterberg limits, plasticity index (Ip), specific gravity, standard compaction properties, unconfined compressive strength, and the un-soaked California bearing ratio (CBR). The study found that adding a 5% mixture of marble powder made the California bearing ratio value go up by 175.49% and the unconfined compressive strength (UCS) value go up by 23.27%. This incorporation led to a decrease in the compressibility and swelling pressure of the examined clay soil in comparison to the soil containing just clay.