Surface modification is crucial for conferring novel functionalities to objects and interfaces. However, simple yet versatile strategies for the surface modification of multiple classes of nanomaterials, including biointerfaces, are rare, as the chemical interactions between the surface modifiers and the substrates need to be tailored on a case-by-case basis. Recently, metal-phenolic networks (MPNs) have emerged as a versatile surface modifier based on the universal adherent properties of phenolic molecules, namely the constituent gallol and catechol groups. Additionally, the dynamic interactions between metal ions and phenolic molecules confer additional functionalities to the MPNs, such as stimuli-responsiveness. Given the interest in MPNs for nanomaterial and biointerface engineering, this review aims to provide an overview of the assembly process, physicochemical properties and applications of MPN coatings.