Immunosensors are analytical devices that combine the specificity of antibodies with various transduction methods to detect contaminants in food. They offer rapid, sensitive, on-site detection of pathogens, toxins, allergens, and chemical residues, enhancing food safety monitoring. This chapter provides an overview of immunosensor principles, including surface plasmon resonance, ellipsometry, optical waveguides, microgravimetric sensors, and their applications in food safety. Recent advancements, such as nanostructured materials and electrochemical detection techniques, have improved immunosensor performance, enabling real-time monitoring and early detection of foodborne hazards. The chapter also discusses current challenges, including the need for standardized protocols and the addressing of non-specific binding. It explores future directions for integrating immunosensors into food safety management systems.