This study was conducted to investigate the effects of irrigation water with different salt (NaCl) concentrations (T0: pure water; T1: 1 dS m^-1; T2: 2 dS m^-1; T3: 3 dS m^-1) on the following: the germination rate, the germination time, the root length, and the plant growth of tomato (Solanum lycopersicum L.) seeds. In the present study, two tomato varieties, designated as SC21-21 and H-2274, were utilised for the experimental purposes. The process of seed germination was conducted within a laboratory setting, under controlled in vitro conditions, on a filter paper substrate maintained at a temperature of 25 °C. The findings of the study demonstrated that an increase in salt concentrations led to a decline in germination percentage, an extension in germination time, and a negative impact on root length and plant growth in both tomato varieties. The germination rate was found to be 97.33% in the control group (T0) of the SC21-21 variety, however this rate decreased to 60% at the highest salt concentration (T3). In the H-2274 variety, the germination rate was determined as 57.33% at T3, while it was 78.67% in the control group (T0). With regard to root length, the maximum value recorded was 19 cm in the control group; this value decreased to 9.167 cm as salt concentration increased. The findings of the study indicated that elevating the sodium chloride content had deleterious consequences on the germination and development of tomato seeds. The SC21-21 variety demonstrated a higher germination rate in comparison to the H-2274 variety when subjected to salt stress. In regions where salinity problems are pervasive, the selection of salt-resistant genotypes is paramount for the long-term viability of agricultural productivity.