The rapid urbanization observed in both developed and developing nations has led to a significant increase in the production of Granulated Blast Furnace Slag (GGBS), a byproduct of the iron and steel industry commonly utilized as supplementary materials in concrete. However, this surge in waste generation has resulted in substantial social challenges, including airborne dust pollution and the scarcity of land for safe disposal, particularly in urban settings. This study aims to enhance soil strength by incorporating varying proportions of GGBS. Given the low plasticity indicated by the natural soil's index properties, sodium bentonite (with a Liquid Limit of 302%) was introduced to the soil, forming a blend comprising 50% natural soil and 50% bentonite. Laboratory tests were then conducted to assess the impact of GGBS on both index and engineering properties of the soft clay, ranging from 0 to 50% GGBS content. The addition of GGBS resulted in a notable reduction in the Free Swell Index of the bentonite-admixed soil, decreasing by 50.4% with a 30% GGBS incorporation. Furthermore, the Unconfined Compressive Strength of the bentonite-admixed soil exhibited a substantial increase from 113.58 kN/m2 to 193.43 kN/m2 at the 30% GGBS level, thereafter remaining relatively stable even with higher GGBS percentages. Hence, the potential of GGBS as a beneficial additive for soil stabilization, offering promising solutions for addressing urban waste management challenges and enhancing infrastructure resilience is witnessed.