An endpoint computing device multi-network slice utilization system includes a RAN system coupled to a core network system that allocates network slices and makes each of them available for use in wireless communications. An endpoint computing device includes applications and operates, for each of its applications, to detect that application, determine a networking connectivity requirement for that application, and identify one of the network slices that is allocated by the core network system, available via the RAN system, and that satisfies the networking connectivity requirement for that application. The endpoint computing device then establishes a connection for each of its application with the one of the network slices that satisfies the networking connectivity requirement for that application, and exchanges communications via the RAN system and the core network system for that application using the one of the network slices that satisfies the networking connectivity requirement for that application.