This study investigates the effects of different biostimulants on the growth, yield, and stress tolerance of tomato plants. Biostimulants such as humic substances, seaweed extracts, and protein hydrolysates were applied to tomato plants grown under both normal and salt-stress conditions. The results showed that all biostimulant treatments improved plant growth, fruit yield, and quality compared to untreated controls. Under salt stress, biostimulanttreated plants maintained higher chlorophyll content, relative water content, and membrane stability, indicating better stress tolerance. These findings suggest that biostimulants can enhance tomato production and help plants cope with environmental stress, making them valuable tools for sustainable agriculture. The study highlights the importance of integrating biostimulants into crop management practices to increase productivity while reducing environmental impact.