Excessive use of synthetic fertilizers has caused serious environmental and health concerns. In this context, bio-stimulants such as seaweed extract and organic fertilizers like chicken manure can play a vital role in mitigating these impacts and improve crop performance. Two field experiments were conducted over two successive summer seasons to evaluate the effects of foliar seaweed extract (SWE) (0 mL/L, 2 mL/L, 4 mL/L) and chicken manure (ChM) (0 t/ha, 11. t/ha 9, 23.81 t/ha) in combination with 75% of the recommended nitrogen rate on growth, yield components, total yield, and fruit quality of tomato (Solanum lycopersicum L., cv. Red Jayda). Nine selected treatments, including a control, were tested to assess the interaction of SWE and ChM at reduced nitrogen. The results indicated that combining chicken manure and seaweed extract with a reduced nitrogen fertilizer rate (75% of the recommended level) significantly enhanced tomato growth, yield, and fruit quality. Foliar application of seaweed extract four times, in combination with 75% of the recommended mineral fertilizer dose and without chicken manure, significantly increased tomato yield. Total yield increased by 38.04% and 36.13% at an application rate of 2 mL/L during the first and second seasons, respectively. Increasing the concentration to 4 mL/L further enhanced yield by 49.81% and 48.26% per hectare in the first and second seasons, respectively, compared with the treatment receiving the same fertilizer rate without seaweed extract. These results indicate that the use of seaweed extract can reduce mineral nitrogen fertilizer input by up to 25% while maintaining or improving tomato productivity. Fruit quality also improved significantly, as reflected by higher nitrogen, phosphorus, potassium, and protein contents. Overall, these findings demonstrate that integrating organic fertilization and seaweed extract bio-stimulants offers a sustainable strategy to enhance tomato productivity, improve fruit quality, and reduce reliance on chemical fertilizers in semi-arid regions.