Moringa oleifera is a popular edible protein source due to its high concentration of micronutrients, macronutrients, and antioxidants. The present study investigated the effects of M. oleifera leaf at various levels on the growth performance, haematobiochemical response, and SOD2 and HSP70 gene expression of Heteropneustes fossilis for 90 days. The fish were randomly distributed into 12 glass aquaria (66×36×36 cm) at 50 fish/aquarium in triplicate treatments Four dietary groups were used to feed the H. fossilis, each group containing graded levels of M. oleifera leaf meal (0, 10 %, 20 %, and 40 %) with a basal diet. It was observed that H. fossilis fed a diet supplemented with 10 % MOLM produced the highest final weight, specific growth rate, condition factor, and survivability. Hemoglobin and red blood cell levels were significantly higher in the fish treatment fed with a 10 % M. oleifera diet compared to the other treatments. Significantly lower levels of ALT and AST were detected in the fish that were fed a diet containing 10 % MOLM. Frequencies of ECA and ENA were significantly higher at 40 % M. oleifera inclusion. The relative mRNA expression profile of SOD2 and HSP70 gene were significantly higher at 10 % MOLM supplementation diet in comparison to the control group. The results of the PCA showed that adding 10 % MOLM supplementation had a beneficial effect on the nutritional and haematobiochemical parameters. Overall, it can be stated that 10 % MOLM treated with basal diet as a supplement on stinging catfish have positive impact on growth performance, haematobiochemical response, and immune gene expression.