A learning device is configured to perform learning of a decision tree, and includes: a plurality of learning units each corresponding to a data memory of a plurality of data memories, and being configured to perform learning at a first node using learning data acquired by using first addresses related to a storage destination of the learning data corresponding to the first node of the decision tree in the data memory, and output a second address related to a storage destination of each piece of the learning data branched from the first node; and a plurality of managers each corresponding to a learning unit of the plurality of learning units, and being configured to calculate third addresses related to storage destinations of learning data corresponding to second nodes being next nodes of the first node using the first addresses and the second address output from the learning unit.