Rapid urbanization leads to enormous generation and dumping of Municipal Solid Waste (MSW) at a faster rate and creates environmental problems such as soil, water, and air pollution. At present, the MSW is collected and processed at MSW processing plants, the recyclables are separated, and the rest of the waste is converted to compost. At last, still, there is a significant amount of rejectable waste named MSW reject that will remain unutilized and be sent to landfills. In the quest for sustainable solutions to the rising problem, the stabilization of MSW reject through the addition of cement and Ground Granulated Blast Furnace Slag (GGBS) were planned for experimental investigation. This study investigated the potential for effective reuse of MSW reject and the geotechnical properties of stabilized MSW reject amended with varying proportions of cement and GGBS. The test results found that with the increase in cement and GGBS content, there is an increase in the specific gravity of the MSW reject samples. The California Bearing Ratio (CBR) values were found to be maximum when 15% cement and 15% GGBS were added to MSW reject individually in the case of unsoaked condition at 5 mm penetration. The triaxial test results showed an increase in the cohesion and angle of internal friction when cement and GGBS were added to the MSW reject. The compression index values have been shown to decrease with the addition of cement and GGBS to MSW reject. The present experimental investigation shows that the additives, such as cement and GGBS, were found suitable for improving the geotechnical properties of MSW reject for its best utilization, thus it offers a sustainable solution for its reuse.