Abstract: A modular cosmetic container system is provided to enable a user to organize, create, and substitute customizable cosmetic trays detachably retained within a cosmetic storage system. The present invention utilizes the customizable tray assemblies as a means to store particular combinations of cosmetic products. Each cosmetic product is stored within specially designed receptacles to create a unique set of cosmetic products. These unique sets can be placed within the cosmetic storage system allowing for facilitated transfer and improved customization for user's who may need to frequently carry large collections of cosmetic products. The modular cosmetic container system comprises a housing assembly and at least one tray assembly. The housing assembly is the structural body that functions as a storage location for retaining the at least one tray assembly. The at least one tray assembly is the customizable storage component that retains a plurality of cosmetic products or cosmetic applicator.