Heavy metals (HM) in agricultural soils are a significant threat to crop productivity, adversely affecting plant growth and development through various physiological and biochemical mechanisms. Among the HM, nickel (Ni) has been reported to be increasingly accumulated in the soil and is a serious threat to human health via the food chain. Poor seedlings growth and low-quality produce are major causes of Ni toxicity in plants. The current study aimed to assess the effect of activated pomegranate peel biochar (APPB) on morpho-physiological and biochemical processes of wheat grown in Ni-affected soil. Different treatments i.e. control, biochar, Ni, and biochar + Ni were designed under randomized complete block design with six replications of each treatment. The morphological, biochemical, and physiological responses were then evaluated. Present results revealed the growth decline in wheat seedlings subjected to Ni toxicity. Moreover, disturbances in photosynthetic pigments, metabolites, and thiol group were recorded in seedlings under excess of Ni content. The findings of this study demonstrate that the application of APPB supplementation significantly alleviated the negative effect of Ni on wheat seedlings and improved growth parameters by 171%, 83%, 330%, 78%, and 96% in shoot biomass, shoot length, root biomass, root length, and seedlings dry weight, respectively. Chlorophyll a, b, and total chlorophyll contents boosted by 44%, 83%, and 55%. Carbohydrate content also increased by 82%, while total phenols and flavonoids were reduced by 24% and 22%, respectively. The stunted growth and irregular photosynthesis were recorded in wheat seedlings due to nickel toxicity. Hence, APPB proved to be an effectives soil amendment, that may be used for improved crop growth with enhanced and increasing tolerance to metal stress through the modulation of defense indices.