This study aimed to investigate the chemical composition and physicochemical properties of Ulva intestinalis and its potential application in surimi fortification. Compositional analysis showed that U. intestinalis powder was high in minerals (19%), protein (13.5%), and carbohydrate (57%), but low in lipid (2.7%), though the fatty acid profile comprised appreciable amounts of unsaturated fatty acids (49%) with docosahexaenoic to be the highest ω3 fatty acid. Amino acid analysis indicated the predominance of essential amino acids, which were comparable to FAO/WHO requirements. Regarding the physicochemical properties, the water holding was comparable to some agricultural fiber-rich products. The effect of three levels of U. intestinalis powder (1.4, 2.8, and 4.2 g (100 g)⁻¹) on the characteristics of silver carp surimi, at the constant levels of protein and water in all treatments, revealed an increasing trend in gel strength and water-holding capacity of gels at the concentration of more than 2.8 g (100 g)⁻¹, with a significantly enhanced effect only in water-holding capacity with respect to the control (P < 0.05). The pH values and whiteness of surimi gels decreased significantly as a function of U. intestinalis powder addition, while emulsifying stability of surimi pastes were notably improved (P < 0.05). The products formulated with up to 2.8 g (100 g)⁻¹ seaweed were acceptable sensorially. Overall, the results of this study could be useful in developing surimi products with technological and nutritional benefits of edible seaweeds.