Many sections of the world have heavy metal-contaminated soil, which has a number of negative impacts on plants and threatens the effectiveness of the global food supply. Hazardous and non-essential element cadmium disrupts physiological processes, also having a detrimental impact on a plant's growth, the photosynthetic properties and delaying plant development metabolism. To investigate the impact of cadmium toxicity in Ocimum, pot experiment was carried out. In this work, cadmium (Cd) effects by using the concentrations (0, 100, 150 mg CdCl2 kg−1 of soil) on the physiological, morphological, and biochemical responses of Ocimum grown in greenhouse conditions were examined. Cadmium reached to the soil to decrease the membrane permeability, growth features, relative water content and photosynthetic attributes though the antioxidant enzyme activity augmented when the concentration of Cd increased. Malondialdehyde (MDA), hydrogen peroxide (H2O2), and proline were also higher in the heavy metal stressed plants compared to control plants. By regulating enzyme activities and osmolyte buildup in response to heavy metal stress, this study indicated that Ocimum plants evolved well-developed defence mechanisms.