The geotechnical characteristics of soft soil must be improved to make them favorable for building structures. Researchers are paying attention to using green technologies such as construction and demolition (C&D) waste and geopolymer as a substitute for cement-based stabilization. This paper reviews the strengthening of subgrade for foundations and pavement using C&D wastes and following geopolymer-based stabilization. C&D waste used in geopolymer concrete is also discussed in this paper. Using these constituents together increases UCS soil strength by 1.7–2.3 times than the non-stabilized soil specimen. It has been demonstrated that the geopolymer binder has superior mechanical, physical, and durability qualities, and thus, this method is widely practiced for subgrade stabilization for different civil engineering projects. Further, this paper provides future scope based on the present research gap under the section future agenda.