Metal–phenolic networks (MPNs) are novel supramolecular materials with numerous applications in the field of advanced material science and engineering due to their plentiful fascinating features. Following the first assembling of MPN films on diverse solid surfaces in 2013, MPN materials have attracted much attention in the membrane technology field to improve membrane multifunctionality through membrane surface or matrix modification for membrane structural stability, durability, and filtration efficiency enhancements. Moreover, the incorporation of inorganic nanomaterials, such as nanoparticles, nanotubes, nanorods, and nanosheets, and hydrophilic polymers, for instance, zwitterions and polyvinylpyrrolidone (PVP), can enable further improvements of MPN-based membranes for diverse water filtration applications. This review has critically summarized the recent MPN-based membrane modifications and identified areas that need to be considered in further research to enhance membrane durability, filtration performance, and operational lifetime. Overall, it is foreseen that the novel membranes, as well as an ever-widening scope of membrane applications based on the MPN material, will constantly emerge.