Disease management has become prominent in aquaculture due to emergence of antibiotic resistant pathogens and overuse of chemotherapeutic agents. One among the developmental strategies to control disease outbreak is by enhancing the fish immunity using immunostimulants. The use of dietary herbal immunostimulants can improve the immune defence of fishes, providing resistance against infections. The present study evaluated the possible effects of Limonia acidissima L. fruit (wood apple) supplemented diets on the growth, innate immunity and disease resistance against Aeromonas hydrophila in Catla fish. Catla catla fingerlings (mean weight 5.0 ± 0.5 g) were separated into four groups and cultivated in 100-L tank. Each group was fed with diets supplemented with 0 g, 1.5 g, 3 g and 6 g per 100 g feed twice daily. Fish were examined for growth and innate immune parameters at 30 days interval up to 120 days. Results revealed that wood apple supplemented diets enhanced the growth and innate immune responses of Catla during the feeding trial. Growth performance, haematological parameters, biochemical parameters and immunological indices significantly (p < 0.05) increased in fish fed with experimental diets. The relative survival percentage after A. hydrophila challenge increased in fish fed with Limonia acidissima diet. Thus, the result suggested that fish fed Limonia acidissima Fruit supplemented diet enhanced growth, improved immune system and increased survival rate in C. catla fingerlings.