In this study, an attempt has been made to stabilize/solidify (S/S) contaminated dredged soil collected from Najafgarh drain, New Delhi. Such types of soils are often stabilized/solidified by using ordinary Portland cement (OPC) as stabilizer. But the major concern with this traditional stabilizer is that its production procedure is energy intensive and contributes to CO2 emissions. Ground granulated steel slag (GGSS), with its cementitious properties, can be used as partial replacement of the cement. Hence, in this study, it has been used as OPC replacement and soil stabilizer has been prepared by partially replacing OPC with GGSS (1:1). The laboratory experiments were conducted by adding 4% to 20% of GGSS–OPC mix to the contaminated dredged soil. Results revealed that GGSS-OPC mix effectively S/S the contaminated dredged soil and results were also better in comparison to S/S with OPC only. On the basis of the performance criteria and results obtained, it has been proposed that the contaminated dredged soil after S/S with GGSS-OPC mix can be beneficially used as a construction material for highway subgrade or sub-base.