Heavy metals are major environmental pollutants that have detrimental effects on plant growth human health. Traditional methods for the remediation of heavy metal-contaminated soils are often expensive and ineffective. Nanomaterials (NMs) have emerged as a promising new approach for the mitigation of toxic metals in plants. In this chapter, we discussed the sources, hazards, and mechanisms of heavy metal toxicity in plants. The unique properties of NMs that make them promising candidates for the remediation of heavy metal-contaminated soils and the protection of plants from heavy metal toxicity were summarized. We further summarized the various strategies that plants employ to cope with heavy metal stress, including exclusion, compartmentalization, and detoxification. Furthermore, the different types of NMs that have been used for the mitigation of toxic metals in plants, and the potential mechanisms of NMs are discussed. Finally, the challenges and future prospects of using NMs for the mitigation of toxic metals in plants are discussed.