<p>This study investigated the effects of silica fume on the mechanical properties of cement-stabilized rammed earth (CSRE). The experimental program comprised unconfined compressive strength tests on cubic specimens, as well as splitting tensile and triaxial shear tests on cylindrical specimens. Quasi-static tests were subsequently performed on CSRE walls to evaluate the effect of silica fume on their seismic performance. The results demonstrated that silica fume markedly improved the mechanical properties of CSRE. In particular, the compressive strength, elastic modulus, tensile strength, cohesion, and internal friction angle increased by 58.1%, 51.2%, 53.0%, 50.1%, and 26.7%, respectively. Based on these findings, an empirical equation was established to describe the relationship between the compressive and tensile strengths of CSRE. Although the incorporation of silica fume did not change the failure mode of the CSRE walls, it enhanced their peak load, ultimate displacement, initial stiffness, energy dissipation, ductility coefficient, and peak ground acceleration by 30.9%, 23.5%, 45.6%, 28.0%, 25.0%, and 56.3%, respectively. The results further indicate that CSRE walls with a silica fume content of 10% satisfy the seismic performance requirements of the target region.</p>