Due to the high storage capacity and multiple electron?transfer chemistry of sulfur (S), Li?S battery with virtues of high theoretical capacity/energy density, eco?friendliness and abundant supply has been considered as one of the most promising candidates for next?generation battery systems. The capacity of Li?S battery is much higher than that of traditional metal oxide cathode?based lithium?ion battery, which is regarded as the highest capacity of solid?state cathode?materials at current stage. As a vital component of Li?S battery, separator plays a profound role in resolving crucial issues (e.g., shuttling effect, volume expansion, poor conductivity and metal dendrites, etc.) of Li?S battery. So far, some pioneering works have been reported in the exploration of separators for Li?S battery. On this basis, covalent organic frameworks (COFs), possessing the advantages of low density, high porosity, well?defined structure, designable structure and functions, is a kind of potential materials for the functional modification of Li?S battery separators. This review will summarize the reported works about COFs in Li?S battery separators including their structural characteristics, preparation?methods, application forms and battery properties. It will also provide a brief perspective for the applications of COFs in Li?S battery separators and hope that it might give new insights for scientists in related fields.