In the past few decades, the application of nanotechnology has significantly transformed the area of food safety and security by offering innovative tools and techniques to tackle some major challenges in food safety and sustainability. The nanoencapsulation techniques are often used to enhance the efficacy and delivery of nutrients/bioactive compounds, making them more bioavailable and thus improving food fortification/preservation. Nanoencapsulation in the field of green preservatives is not only helping to address the drawbacks of natural preservative agents but also progressing toward replacing the conventional chemical ensuring a safer and sustainable alternative. Further, nanosensors and nanomaterial-based detection systems ensured the rapid and highly sensitive identification of chemical contaminants, pathogens, and spoilage. Nanotechnology is significantly contributing to food science and technology by improving antimicrobial characteristics and removing present obstacles that extend shelf life, minimize waste, and maintain nutritional quality. However, like every breakthrough, nanotechnology has its shortcomings, which are mainly associated with its unknown long-term side toxicity effects on health and the environment in terms of residual toxicity and bioaccumulation. The chapter highlighted the early emergence of nanotechnology in human civilization and its potential application in food safety and sustainability and discussed regulatory, ethical, and safety concerns to ensure consumer trust and environmental sustainability.