Recent years have shown an increase in awareness from consumers about issues associated with food fraud, adulteration, and safety. Food adulteration is considered an integral part of food safety, and it is a critical process that satisfies legislation, regulations, and consumer demands. Food adulteration is a term that is more frequently used and has been defined as “a collective term used to encompass the deliberate and intentional substitution, addition, tampering, or misrepresentation of food, food ingredients, or food packaging; or false or misleading statements made about a product, for economic gain.” Food adulteration has been part of the food supply and value chains since ancient times, including issues associated with spoilage during shipment and storage; common ways of adulteration were mixing the spoilt food with fresh food and substitution of inferior local products for expensive goods from abroad. Food adulteration also has a direct impact on human health as well as on the sustainability of the food supply and value chains. Usually, foods of great economic value are the ones that are subjected to food adulteration. They include grains, honey, spices (e.g., saffron), olive oil, and wine, to mention a few. This chapter discusses the main definitions, methods, and issues that are of importance in the field of food adulteration.