<p>Antimony (Sb) a toxic heavy metal, has become an increasing threat to agricultural ecosystems due to the growing problem of soil pollution. Sb’s interaction with soil and plant systems disturbs important physiological and biochemical pathways, compromising plant development and food safety. Biochar, a carbon-rich and sustainable soil amendment, has gained attention for its ability to immobilize heavy metals (HMs) and improve plant tolerance under metal stress. However, the specific mechanisms underlying biochar–Sb interactions and their influence on plant defense and signaling systems remain insufficiently understood. This review identifies potential sources of Sb contamination in agricultural systems. It then illuminates the effects of Sb contamination agricultural systems and examines its effects on plant signaling networks, tracing its adsorption from soil to plants. It highlights the role of biochar in Sb remediation by modifying soil chemical properties and microbial activities, thereby positively influencing plant resilience to Sb-induced stress. The findings of this review present a conceptual and mechanistic framework for how biochar application influences Sb mobility, soil chemistry, microbial activity, and plant resilience. Further research is needed to evaluate how diverse climatic conditions influence biochar’s effectiveness and its long-term impact on Sb retention in soil and crop yield.</p> Graphical Abstract <p></p>