Silicon (Si) is reported to reduce the effect of salinity on wheat (Triticum aestivum L.) and other crops. In the present study, Si decreased plant Na⁺ uptake and shoot : root Na⁺ distribution of a salt-resistant as well as a salt-sensitive wheat genotype. Reduced shoot Na⁺ concentration and increased shoot K⁺ : Na⁺ ratio led to improved plant growth. Silicon increased cell-wall Na⁺ binding from 49% in SARC-1 and 37% in 7-Cerros under salinity to 87% in SARC-1 and 79% in 7-Cerros under salinity + silicon. It may also have resulted in decreased potentially toxic leaf sap Na⁺ concentration. The concentration of glutathione, an important antioxidant in plants, was increased due to the addition of Si under saline conditions. The salt-resistant wheat genotype SARC-1 was less Si-responsive in terms of shoot fresh weight, having a 39% increase compared with a 49% increase in 7-Cerros, as well as root fresh weight, having a 12% increase compared with a 22% in 7-Cerros. It is concluded that Si may have improved shoot growth of the salt-resistant as well as the salt-sensitive wheat genotype by decreasing plant Na⁺ uptake and shoot : root Na⁺ distribution as well as by increasing glutathione concentration. Silicon may have also improved in-plant Na⁺ detoxification by increasing cell-wall Na⁺ binding.