Salt stress significantly impairs plant growth, causing disruption in ion balance, oxidative damage, and altered metabolic processes. This study was conducted to investigate the role of hydrogen sulfide (H2S) in mitigating the detrimental effects of NaCl-induced stress in tomato plants. Tomato plants were exposed to NaCl (0, 50 or 150 mM) with or without application of 200 mu M sodium hydrosulfide (NaHS), used as an H2S donor. The results demonstrated that NaCl treatment led to an increase in sodium (Na+) and a decrease in potassium (K+) ion concentrations, disrupting ion homeostasis. However, treatment of H2S resulted in an increase in concentration of K+. Furthermore, H2S mitigated the reduction in growth and photosynthetic attributes under salt stress. H2Sfed plants enhanced the activity of key antioxidant enzymes (CAT, SOD, POX), reducing oxidative damage and membrane instability, as reflected by decreased electrolyte leakage and malondialdehyde content. Metabolic profiling revealed that NaCl treatment altered several metabolites related to osmotic stress and energy production, whereas H2S treatment activated pathways involved in oxidative stress protection, amino acid metabolism, and lipid Signaling. Pathway enrichment analysis further identified significant alterations in amino acid biosynthesis and sulfur metabolism. These findings highlight the potential of H2S as a plant growth regulator in mitigating salt stress by modulating key physiological and biochemical pathways, thereby improving stress tolerance and enhancing overall plant health.