A vehicle seat air-conditioning device includes a vehicle seat, an electric blower, and a plurality of ducts. The vehicle seat includes a plurality of regions. The electric blower includes a plurality of fans and one electric motor. The plurality of fans correspond to the plurality of regions, respectively. The electric blower drives the plurality of fans by the one electric motor to have blowing capacity corresponding to the plurality of regions respectively. Each of the plurality of ducts is provided between a corresponding one of the plurality of regions and a corresponding one of the plurality of fans. An air flow produced by each of the plurality of fans passes through a corresponding one of the plurality of ducts. The air flow passing through each of the plurality of ducts air-conditions or ventilates a corresponding one of the plurality of regions.