The effect of small-dose sodium silicate (SS) solutions with varying compositions on the rheology and early-age strength of limestone calcined clay cement (LC3) was evaluated. SS addition reduced colloidal interactions in LC3, leading to significant reductions in initial yield stress and viscosity, depending on composition. All SS-added systems met the initial setting time requirements of EN 197–1. A solution containing 1 % Na2O and a silicate modulus of 0.4 notably accelerated silicate and aluminate reactions in cement clinker, as well as synergistic reactions between calcined clay and limestone. This resulted in 1-day strength gains of 120 % and 13 % compared to LC3 and CEM I, respectively. Microstructural analysis revealed a denser matrix and refined pore structure at 1 day, consistent with accelerated phase evolution. These results demonstrate that well-formulated SS solutions can significantly enhance both rheology and early-age performance of LC3, supporting their use as effective accelerators in sustainable cement systems.