This pump device 10 is provided with a shaft 41, a motor unit 20 which rotates the shaft 41, and a pump unit 30 which is driven by the motor unit 20 via the shaft 41 and which discharges oil. The pump device 10 comprises a first oil flow path which connects the inside of the pump unit 30 and the inside of a housing 12, a second oil flow path which is disposed between a stator 50 of the motor unit 20 and a rotor 40, a third oil flow path which is disposed radially outside or radially inside of the stator 50 and the rotor 40, and a fourth flow path through which oil from the second flow path or third flow path flows into the pump unit 30.