A storage system and method for namespace reservation in a multi-queue single-controller environment are provided. In one embodiment, a method for access control in a memory is performed in a storage system comprising a memory and a controller in communication with a plurality of hosts, wherein each host comprises its own set of input-output queues but only one host comprises an admin queue. The method comprises receiving a mapping that restricts access to portions of the memory to specific ones of the plurality of hosts, wherein the mapping is generated by the host that comprises the admin queue; and restricting access to the portions of the memory based on the mapping. Other embodiments are provided.