A motor unit includes a motor including a rotor to rotate about a motor axis extending in a horizontal direction, and a stator radially outside of the rotor, 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 feed the oil from the vertically lower region of the housing space to the motor. A channel of the oil passage includes a main reservoir and an auxiliary reservoir to store the oil. Each of the main reservoir and the auxiliary reservoir includes an outflow port to feed the oil to the motor. The main reservoir is located on an upstream side of the auxiliary reservoir in the oil passage. The auxiliary reservoir is structured to receive a portion of the oil overflowing from the main reservoir.