According to one embodiment, a memory system includes a first chip and a second chip. The second chip is bonded with the first chip. The memory system includes a semiconductor memory device and a memory controller. The semiconductor memory device includes a memory cell array, a peripheral circuit, and an input/output module. The memory controller is configured to receive an instruction from an external host device and control the semiconductor memory device via the input/output module. The first chip includes the memory cell array. The second chip includes the peripheral circuit, the input/output module, and the memory controller.