This study investigates the potential for controlling and reducing dispersivity in dispersive clay soils through the use of additive combinations of cement and nanosilica. The necessity of this research arises from the fact that soil dispersivity poses a serious threat to the stability of civil engineering projects, making the identification of an optimal stabilization blend crucial. To achieve the objectives of the study, laboratory tests including unconfined compressive strength (UCS), direct shear, and double hydrometer tests were conducted. The base dispersive clay was treated with three levels of cement (5%, 10%, and 15% by dry weight of soil) and three levels of nanosilica (0.4%, 0.8%, and 1.2%), resulting in nine stabilization scenarios along with a control scenario (no additive). The results indicated that even the combination of 5% cement with 1.2% nanosilica was effective in mitigating soil dispersivity. However, the optimal mix was identified as 10% cement with 0.8% nanosilica (Scenario S22), which exhibited the highest compressive and shear strength, uniform behavior, and complete non-dispersivity. Direct shear results showed a 3 to 7-fold increase in shear strength compared to the untreated soil, along with behavioral stability under increasing confining stresses. Nanosilica played a key role in reducing result variability and improving repeatability. The combined use of cement and nanosilica offers an effective, , and reliable method for stabilizing dispersive clay soils. The proposed optimal combination not only significantly improves mechanical strength but also outperforms other mixtures in terms of behavioral stability and dispersivity control. The ability of nanosilica to enhance uniformity and reduce variability is a distinct advantage of this approach.