The unsustainable practices of human activities have led to the unbalanced introduction of xenobiotics into the environment. A wide range of pollutants, including heavy metals, dyes, pesticides, phenols, detergents, hydrocarbons, medicines, fertilizers, and several others, are released daily into the air, soil, and water. To solve the environmental issues, nanotechnology has achieved significant advancements. In the recent past, synergizing algae with nanotechnology applications in the field of environmental remediation has gained momentum. This technology is being explored for application in the remediation of heavy metal, dye, and other pollutants in water and industrial waste. The main mechanisms used by different algae species to remediate a variety of prevalent and emerging contaminants are bio-uptake, bioadsorption, photodegradation, and biodegradation. The applications of nanomaterials synthesized from algae have opened a novel frontier in phyconanotechnology. The nano-based bio adsorbent derived from algae has numerous advantages due to its high adsorption efficiency, affordability, and availability. The remediation of pollutants by phyconanomaterials has shown to be more efficient than traditional phycoremediation. Besides the uses of phyco-nanotechnology in remediating heavy metals and dyes, it can be exploited for the remediation of pharmaceutical waste, herbicides, pesticides, and antifouling of wastewater effluent. This chapter discusses the recent developments in the remediation of environmental pollutants by phyconanomaterials, their degradation mechanism, and their future prospects.