Environmental pollution caused by industrialization, urbanization, agricultural intensification, and population growth has become a major global challenge. Contamination of air, water, and soil by toxic chemicals, heavy metals, dyes, pesticides, pharmaceuticals, microplastics, and greenhouse gases threatens ecosystems and human health. Conventional remediation technologies often suffer from limitations such as high operational cost, low efficiency, incomplete pollutant removal, secondary contamination, and energy-intensive processes. In recent years, nanotechnology has emerged as a promising interdisciplinary field for addressing environmental problems through the development of advanced nanomaterials with unique physicochemical properties. Sustainable nanotechnology combines green chemistry principles with nanoscale engineering to create environmentally friendly materials and remediation systems. This review article comprehensively discusses recent advances in sustainable nanotechnology for environmental remediation, including green synthesis approaches, nanomaterial classifications, pollutant removal mechanisms, water treatment technologies, air purification systems, soil remediation strategies, photocatalysis, antimicrobial applications, and waste management. The article further highlights the environmental risks, toxicity concerns, regulatory challenges, commercialization barriers, and future opportunities associated with nanotechnology-based remediation systems. The integration of nanotechnology with biotechnology, artificial intelligence, circular economy principles, and renewable energy systems is expected to revolutionize environmental management and sustainable development.