Black cotton soil is an expansive soil widely found in India, known for its high clay content and significant swelling and shrinkage behavior, making it unsuitable for construction without stabilization. This study focuses on improving its stability and strength using marble dust and burnt brick powder, which are industrial waste materials. Marble dust (rich in calcium carbonate) and burnt brick powder (containing silica and alumina) help form cementitious compounds that enhance soil cohesion, reduce plasticity, and minimize swelling. Laboratory tests such as Atterberg limits, compaction, UCS, and CBR were conducted. Results show significant improvement in strength, density, and load-bearing capacity, providing an economical and eco-friendly solution for construction works.