Cell membranes have recently emerged as a new source of materials for molecular delivery systems. Cell membranes have been extruded or sonicated to make nanoscale vesicles. Unlike synthetic lipid or polymeric nanoparticles, cell membrane-derived vesicles have a unique multicomponent feature, comprising lipids, proteins, and carbohydrates. Because cell membrane-derived vesicles contain the intrinsic functionalities and signaling networks of their parent cells, they can overcome various obstacles encountered in vivo. Moreover, the different natural combinations of membranes from various cell sources expand the range of cell membrane-derived vesicles, creating an entirely new category of drug-delivery systems. Cell membrane-derived vesicles can carry therapeutic agents within their interior or can coat the surfaces of drug-loaded core nanoparticles. Cell membranes typically come from single cell sources, including red blood cells, platelets, immune cells, stem cells, and cancer cells. However, recent studies have reported hybrid sources from two different types of cells. This review will summarize approaches for manufacturing cell membrane-derived vesicles and treatment applications of various types of cell membrane-derived drug-delivery systems, and discuss challenges and future directions.