Mine tailings, the residual waste materials from mining operations, pose significant environmental challenges due to their hazardous nature and long-term storage requirements. This study investigates the feasibility of utilizing mine tailings as a partial replacement for fine aggregates in masonry grout. The primary objectives include determining the optimal percentage replacement of mine tailings that yield the highest compressive strength, comparing different replacement levels against the ASTM C476 standard, and assessing the consistency of the grout mix. An experimental method was employed, incorporating mine tailings at replacement levels of 0%, 10%, 20%, 30%, and 40% by volume. The study followed ASTM standards for mixing, curing, and testing, with compressive strength tests conducted after a 28-day curing period. Results indicated that a 20% replacement level achieved the highest mean compressive strength of 3584 psi (24.71 MPa), exceeding the minimum required strength of 2000 psi (13.79 MPa). Additionally, grout mixes with 10% and 20% mine tailings demonstrated superior strength compared to the control sample. However, further increases in tailings content reduced compressive strength and workability. The findings suggest that mine tailings can be a viable alternative to natural sand in masonry grout, contributing to sustainable waste management in the mining and construction industries. Further research is recommended to explore the chemical properties of mine tailings and optimize their incorporation into construction materials.