Fungi play a powerful but often overlooked role in cleaning up pollution and restoring damaged ecosystems. This review shows that certain fungi can break down 80–95% of toxic organic pollutants like petroleum hydrocarbons and dyes within days to weeks, remove 75–98% of heavy metals such as lead, cadmium, and copper from contaminated soil and water, and even degrade plastics, with some species reducing polyurethane mass by 30–60% in under 8 weeks. Fungal mycelium has also been used in real-world filtration systems, cutting nutrient runoff and bacteria in waterways by 60–90%, while fungal biofilters can remove 70–95% of harmful air pollutants like toluene and xylene.