Configurable three-dimensional neural network array. In an exemplary embodiment, a three-dimensional (3D) neural network array includes a plurality of stacked synapse layers having a first orientation, and a plurality of synapse lines having a second orientation and passing through the synapse layers. The neural network array also includes synapse elements connected between the synapse layers and synapse lines. Each synapse element includes a programmable resistive element. The neural network array also includes a plurality of output neurons, and a plurality of select transistors connected between the synapse lines and the output neurons. The gate terminals of the select transistors receive input signals.