This study aims to get a comprehensive evaluation of the growth promoting effects and the hypoxic stress relief potentiality of Moringa oleifera aqueous extracts. Oreochromis niloticus fingerlings were arbitrarily allocated into five duplicated fish groups (30 fish tank-1). The fish groups were labeled according to the M. oleifera aqueous extract dietary inclusion level (G1:G5). MOAE had fundamentally promoted tilapia growth. Serum total protein levels were considerably higher in the M. oleifera fed fish, whereas the levels of liver enzymes diminished significantly in G5 fish. Additionally, the dietary M. oleifera resulted in a noticeable hypoglycemic effect together with a pronounced decline in the antioxidant activities. The use of M. oleifera supplemented diet decreased the hypoxia-related stress as conveyed by the gradual descent in the serum cortisol levels of the hypoxic-stressed tilapia. This study proposes the potentiality of M. oleifera aqueous extract as a growth promoter, antistress and antioxidants. It also validates its safe application in commercial tilapia culture. Future study is required to comprehend the influence of this plant extract in relieving chronic stress and its possible toxic effect as well. Feasibility study for its commercial usage is required too.