Cement manufacturing is energy-intensive, emits greenhouse gases, and is costly. To address these challenges, the construction industry seeks sustainable alternatives. This study explores the use of Termite Hill Soil (THS) as a partial replacement for ordinary Portland cement (OPC) in mortar production. Various mixtures were prepared with different proportions of THS (0%, 5%, 10%, 15% and 20%) while maintaining a constant water-to-cement ratio. The physical, chemical, fresh properties, mechanical, durability, and microstructural properties were investigated using various analytical techniques like SEM, FTIR, TGA, and DTA. THS exhibited pozzolanic properties and had a porous surface with irregular and angular edges. The results showed that the workability and setting time decreased and quantity of water required for attaining normal consistency increased as the THS content increased. The compressive strength of the mortar increased by 9.5% with 5% THS and reached 98% with 10% THS compared to the control mix. THS5 and THS10 significantly improved the compressive strength, bulk density, and ultrasonic pulse velocity, especially in older mortars. Microstructural analysis revealed high density in THS5 and THS10 mixtures. Additionally, the thermal stability of THS increased with higher replacement percentages, and showed little loss of mass due to increasing temperature. It is safe to use for small and medium scale construction works up to 9 % replacement level. Key Words: Termite hill Soil; Supplementary Cementitious Materials; Fresh Properties; Mechanical Properties; Mortar