<p>Plants face multiple abiotic stresses, and toxic heavy metals (HMs) hold the top position because of their toxic impacts on plants. HM stress severely hinders plant growth, development, and agronomic characteristics. HM contamination of agricultural soils, especially at the soil-plant interface of food crops, often leads to food safety and security. New strategies, especially those utilizing the potential of biogenic nanoparticles to mitigate the toxic impacts of HMs and enhance plant growth under HM stress, are gaining momentum. Biogenic NPs have several advantages over their physical and chemical counterparts, including ease of synthesis and functionalization and eco-safety. Biogenic NPs can be applied in various ways, such as foliar applications, seed priming, root applications, and soil amendments, and several recent reports have demonstrated their potential for producing HM-tolerant crops. This review aims to provide readers with an in-depth, detailed, critical, and comprehensive account of the current understanding and updates on different biogenic/green NPs, ways to synthesize or functionalize them, and their exploration for agricultural applications. It discusses mechanistic insights into how green NPs potentially mitigate the negative impacts of HMs on plants, including at molecular and cellular levels, that can be explored for addressing HM toxicity in crop plants. Further, the crosstalk among NPs and other entities, including reactive oxygen species and phytohormones under HM stress, are also discussed. In the end, the environmental and Safety considerations have been presented.</p>