<p>This review aims to integrate current insights into the interactive roles of biochar and zinc (Zn) in nutrient management and phytohormone regulation, emphasizing their combined potential for climate-smart and sustainable agriculture. It highlights how Zn-biochar interactions affect soil fertility, nutrient cycling, phytohormonal balance and overall plant growth. It also addresses global challenges such as micronutrient malnutrition and environmental degradation. Relevant peer-reviewed studies were critically examined to assess how biochar applications affect Zn availability, soil physicochemical traits and mechanism of phytohormone signalling. The review integrates findings across soil-plant-microbe interactions, highlighting mechanistic connections between Zn bioavailability, auxin-cytokinin modulation and root system architecture. Evidence shows that biochar enhances soil structure, cation exchange capacity and Zn retention, while also promoting microbial activity and beneficial root-microbe associations. Zinc supplementation contributes to enzyme function, antioxidant defence and phytohormone-mediated stress resilience. Together, Zn-biochar systems enhance nutrient-use efficiency, crop productivity and Zn biofortification. They also contribute to carbon sequestration, reduced fertilizer inputs and lower greenhouse gas emissions. The combined use of Zn and biochar offers a valuable strategy for developing nutrient-efficient, low-emission and resilient agricultural systems. However, further interdisciplinary research is needed to elucidate biochar-Zn-phytohormone interactions across soil types and cropping systems. Translating these findings into scalable, field-based nutrient management strategies remains essential for achieving global sustainability goals.</p> Graphical Abstract <p></p>