Salinity stress is a significant abiotic factor that limits the yield and quality of sugar beet grown in newly reclaimed saline lands. The field experiment was conducted at a private farm in Tamia (29° 17ˋ N, 30° 53ˋ E), Fayoum, Egypt, in 2021/2022 and 2022/2023 successive seasons. The objective of this study was to assess the usefulness of potassium silicate (K₂SiO₃) in four K-silicate foliar spray concentrations in alleviating salinity stress on five sugar beet varieties grown in saline soil. A split-plot design in a randomized complete block arrangement was used with three replications. Spraying K-silicate showed improved sugar beet varieties' tolerance to soil salinity. Increasing the concentration of the sprayed K-silicate gave higher root and sugar yield productivity. Results showed that the varieties significantly differed, where the Narmar and Afendra varieties showed superiority over the other three tested varieties, with the highest values of root and sugar yield and it is related traits in both seasons. The potassium silicate rate of 2,000 mg/L gave the highest juice quality and lowest impurities, suggesting a great potential for using potassium silicates with sugar beet to produce high roots and quality for economical sugar production under saline soil. The sugar beet varieties with less than one unit of salinity tolerance index (STI), yield stability index (YSI), and salinity susceptibility index (SSI) values were suitable for cultivation under saline soil stress and non-stress environments. These indices were more effective in identifying high-yielding varieties under saline soil stress as well as non-stress conditions.