The use of saline water in agriculture is increasing these decades due to the scarcity of fresh water. The use of silicon nanoparticles is a new approach that can alleviate the adverse effect of saline water on plant growth. The current study was carried out to evaluate the impact of silicon nanoparticles (BSNPs) under salinity stress on seed germination and seedling growth parameters of faba bean (Vicia Faba L.) seedling. The research investigated the interaction between six BSNPs (0, 1500, 3000, 4500, 6000, and 7500 mgL-1) and five salinity levels (freshwater: seawater) (0.70, 1.1, 1.6, 2.1, and 3.1 dSm-1). The results revealed a significant decrease in the germination percentage (GP) with increasing salinity levels for the seeds primed in freshwater than that primed in fresh water and BSNPs. Salinity adversely affected the length of the faba bean radicle for seeds priming in freshwater or in fresh water and BSNPs. This was more noticeable for the seeds primed in freshwater than the seeds primed in BSNPs at high salinity levels. The priming in BSNPs significantly reduced the radius of the root seedlings and the priming in 7500 mgL-1 gave the lowest value for the radius of the radicle. The Increase in salinity levels decreased the total biomass of faba bean for seeds primed in fresh water, contrary to seeds primed in BSNPs. Vigor and salt tolerance indices were significantly affected by levels of salinity, BSNP treatments, and interactions. The study concluded that BSNPs are alleviating material that can used to enhance germination and growth parameters of plants under salinity stress. Moreover, these results highlighted the positive effects of silicon nanoparticles synthesized from rice straw on reducing the harmful effects of high levels of salinity.