A motor unit includes a motor, a housing including a housing space to house the motor, oil in a vertically lower region of the housing space, and an oil passage to lead the oil from the vertically lower region of the housing space through the motor to the vertically lower region of the housing space. The oil passage includes a first oil passage extending through an inside of the motor, and a second oil passage extending through an outside of the motor. One of the first oil passage and the second oil passage includes a cooler to cool the oil therein.