A motion information processing apparatus according to an embodiment includes processing circuitry. The processing circuitry obtains pieces of motion information of a subject acquired from mutually-different positions with respect to the subject performing a predetermined motion. The processing circuitry calculates association information used for bringing the pieces of motion information obtained into association with one another. The processing circuitry exercises control so as to cause an output circuitry to output such output information in which the pieces of motion information are kept in association with one another on the basis of the association information calculated.