Food safety is a growing global concern, with rising cases of foodborne illnesses, allergens, and chemical contamination threatening public health. Traditional detection methods, while effective, are often slow and require complex lab work. Nanotechnology has emerged as a powerful tool to address these challenges, offering faster, more sensitive, and more accurate ways to detect harmful substances in food. By using materials like gold and silver nanoparticles, graphene, and quantum dots, researchers have developed advanced sensors that can identify bacteria, toxins, and allergens even at very low levels. These sensors can be built into smart packaging, handheld devices, or lab-on-a-chip systems, making it easier to monitor food safety in real time from production to consumption. While the benefits are clear, there are still challenges to overcome—such as cost, regulation, and public trust. This review explores how nanotechnology is changing the way we keep our food safe and what lies ahead for the future.