Systems, apparatuses, and methods related to multiple artificial neural networks (ANNs) in memory. Such ANNs can be implemented within a memory system (including a number of memory devices) at different granularities. For example, multiple ANNs can be implemented within a single memory device and/or a single ANN can be implemented over multiple memory devices (such that multiple memory devices are configured as a single ANN). The memory system having multiple ANNs can operate each ANN independently from each other such that multiple ANN operations can be concurrently performed.