Environmental sustainability has emerged as a guiding concept for development across the globe. Numerous pollutants in the air, water, and soil have gobbled up the environment, causing catastrophic damage to humans and other living species. Tackling water shortage and pollution is critical for combating global environmental challenges, necessitating the development of novel solutions for efficient water, air purification, or pollution control. Novel bionanocomposites are proof of green solutions that show prospects for remediation of the environment from pollutants, before and even after their application owing to their eco-friendliness. This chapter discusses bionanocomposites, prevalent air, and water pollutants and their negative impact, bionanocomposites fabrication methods, remediation strategies, and the application of bionanocomposites in environmental remediation. The significance and performance of bionanocomposites and hybrid bionanocomposites are discussed along with their physicochemical properties, including large surface area, thermal stability, and varied functionalization, which are crucial in dealing with the issues of environmental pollution. A case study in China on air and water purification and regulations has been provided. Furthermore, challenges faced in the fabrication and application of bionanocomposites and future outlook have been discussed.