The interaction between phenolics and proteins is one of the most research areas in food, pharmaceutical, and cosmetic fields since these interactions affect the functional properties of proteins and phenolics. By using this phenomena, organoleptic properties of phenolic compounds can be engineered, foaming and gelling properties of proteins can be increased, and also novel delivery platforms for phenolics can be designed. During the construction of phenolic-protein interaction, both covalent and non-covalent bonds occur. Formation of these bonds depends on the type of phenolic compounds and protein and also environmental conditions such as pH, temperature and ionic strengths. Understanding the exact mechanism behind these interactions are leading to generate tunable food, drug, and cosmetic products.