Infectious diseases usually occur in response to the highly intensive rearing conditions in fish farms. The use of feed additives is still one of the most practical options in the field of aquaculture. Therefore, this study aimed at evaluating the impact of raffinose on the growth rate, antioxidative status, and immunity of Nile tilapia. For 60 days, fish fed five test diets with raffinose at 0, 0.5, 1, 1.5, and 2 g/kg. The FBW was increased by feeding raffinose at 0.5 or 1 g/kg levels over the control, whereas no significances were observed among the other groups. Feeding tilapia with raffinose at 1 g/kg increased the WG and SGR and decreased the FCR with regards to the control. The activity of SOD was enhanced by feeding raffinose at all levels, while GPX and SOD were improved by 1 or 1.5 g/kg levels over the control. On the contrary, the concentration of MDA was decreased by raffinose, and the lowest levels were observed by 1 or 1.5 g/kg levels. The lysozyme activity was increased by level 1 g/kg over the other levels without significant differences with 1.5 g/kg. The phagocytic activity and index were also boosted by feeding raffinose at 1, 1.5, and 2 g/kg levels over 0 and 0.5 g/kg. Taking together, dietary raffinose increases Nile tilapia growth performances, and immune responses and 0.85–1.37 g raffinose per kg diet is recommended for this species nutrition.