A pot experiment was conducted to investigate the effects of silicon (Si) on morpho-physiological and bio-chemical traits of maize under different irrigation regimes. Experimental treatments comprised of irrigations [60% and 100% of field capacity (FC)], treatments (0, 50, 100, 150, 200 mg kg−1 CaO4Si) and growing stages (GS) [7th (first) and 14th (second) days of water restriction]. 150 mg kg−1 Si increased the growth of maize by inducing transpiration rate (67.56%), water use efficiency (138.36%) and seedling length (19.83%) at first GS whilst enhanced carotenoids (10.95%), total phenolic compounds (45.04%) and decreased proline (7.87%) at the second GS of 60% treatment. In addition, 200 mg kg−1 Si elevated photosynthesis rate (40.54%), total antioxidant activity (12.69%) and decreased proline (52.77%) at the first GS while increased total anthocyanin content (14.99%) during the second GS of 60% application. Silicon had positive impacts on maize under full irrigation conditions too such that 150 mg kg−1 Si reduced transpiration rate (48.43%) and induced total antioxidant activity (39.95%) at first GS while 200 mg kg−1 Si increased water use efficiency by 144.30% at the second GS. In conclusion Si increased drought resistance due to increasing application doses, and on contrary of the literature, Si positively affected many characters at well-watered environment.