The increasing incidences of heavy metal contamination in aquatic ecosystems, driven by swift industrialization, present a significant risk to both ecosystem and public health. Conventional remediation techniques like chemical precipitation, ion exchange, and membrane filtration frequently encounter challenges concerning cost, effectiveness at low metal concentrations, and the potential for secondary pollution. The application of fungi for the detoxification or removal of heavy metals, known as mycoremediation, has surfaced as a sustainable and effective alternative. This chapter provides an in-depth examination of the principles, mechanisms, and applications of mycoremediation in the context of wastewater treatment. This study delves into significant fungal species such as Aspergillus, Penicillium, Phanerochaete chrysosporium, and Pleurotus, which exhibit robust metal-binding abilities via biosorption, bioaccumulation, biotransformation, and bioleaching processes. This chapter examines the incorporation of fungi throughout different phases of wastewater treatment, as well as the application of agricultural and industrial waste as substrates for fungal growth. In light of the obstacles associated with field scalability, microbial competition, and biomass disposal, recent advancements in genetic engineering, immobilization techniques, and bioreactor design present considerable potential. This chapter highlights mycoremediation as an economical and environmentally sustainable approach to addressing heavy metal contamination in wastewater systems.