In a drive device, a housing includes an outer lid that covers one side in an axial direction of a motor shaft. A pump includes an external gear fixed to an end on one side in the axial direction of the motor shaft, an internal gear surrounding a radial outside of the external gear and meshing with the external gear, a pump room recessed from a surface on the other side in the axial direction of an outer lid toward one side in the axial direction, the pump room accommodating the internal gear and the external gear, a suction port through which the oil is to be sucked into the pump room, and a discharge port through which the oil is to be discharged from the pump room. The motor shaft includes a motor shaft body to which a rotor core is fixed and a closer fixed to the motor shaft body to overlap the internal gear, and close at least a portion of the opening on the other side in the axial direction of the pump room.