Nanotechnology is a transformative tool in sustainable engineering, with innovative applications in agriculture, water purification, and healthcare. It allows for precise drug delivery, targeted pest control, and real-time soil and crop health monitoring. In agriculture, nanofertilizers drive better nutrient utilization and crop yields, reduce chemical runoff, and improve pest management with nano pesticides. For resource conservation, nano biosensors have been applied to monitor environmental conditions. Nanomaterials are critical to meet global challenges, ranging from pollution control to resource efficiency. Quantum dot solar cells use nanoscale semiconductors to exceed the efficiency rates of other renewable energy technologies. Nanomaterials such as carbon nanotubes and nanocellulose significantly improve water purification by effectively removing pollutants and pathogens, guaranteeing fresh and clean water. Nanomedicine applies nanotechnology to revolutionize healthcare by enabling highly precise diagnosis and targeted treatment at the molecular level, minimizing damage to healthy cells. Innovative drug delivery systems in nanomedicine minimize side effects through surface tailoring, controlled nanosize, and high bioavailability. Nanoparticle-based case studies in sustainable engineering demonstrate properties suitable for eco-friendly, biodegradable, and low-toxicity synthesis. These approaches can strengthen diagnostics and personalized medicine, unlocking new industrial applications for a greener future. Despite their promise, high production costs, limited scalability, and considerable regulatory and ethical concerns are some of the challenges for the nanomaterials. Nanomaterials are used in various fields for sustainable development. These technologies show their capacity to mitigate environmental impacts, improve resource efficiency, and contribute to better health outcomes.