Infrastructure needs internationally outweigh concrete demand even as the need for urbanisation continues to increase daily. The management of solid waste is another issue that developing countries struggle with the most. A significant necessity in the construction activities is met by the concrete, which contains cement as the binding material. Although cement has several benefits, such as an outstanding capacity to bind materials together in concrete and a superior material to improve concrete’s strength, it also has a significant negative influence on the environment when it is being produced. The ecology is harmed by the release of carbon dioxide into the atmosphere. Therefore, we must use huge solid waste, such as waste groundnut shells and certain other industrial by-products like flyash and silicafume, effectively. The goal of this research is to employ waste groundnut shell ashes in cement mortar at a 1:3 ratio as an alternative for cement along with optimum flyash and silicafume combinations. As an alternative to cement, groundnut shell ashes are substituted at 0%, 5%, 10%, 15%, and 20%. The results of the compressive strength test indicate that the 10% groundnut shell ash gave a higher compressive strength than the traditional mortar mix at 7 and 28 days. Furthermore, the flexural strength of the cement mortar mixes was assessed at 28 days, with the 10% groundnut shell ash mixture demonstrating enhanced strength. This study suggests that the incorporation of groundnut shells into cement mortar can be an effective strategy for mitigating the carbon dioxide emissions associated with cement production to a certain extent.