A motor unit includes a motor including a rotor and a stator, a gear connected to the rotor, a housing including a housing space to house the motor and the gear, 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 to be fed to the motor. The housing space includes a motor chamber to house the motor; and a gear chamber to house the gear. The housing includes a partition to divide the motor chamber and the gear chamber. A bottom portion of the motor chamber is higher than a bottom portion of the gear chamber. A portion of the oil fed to the motor is in a vertically lower region of the motor chamber. A vertically lower region of the partition includes a partition opening to bring the gear chamber and the motor chamber into communication with each other. The partition opening is structured such that a rise in a liquid surface of the oil in the vertically lower region of the motor chamber causes an increase in an amount of transfer of the oil from the motor chamber to the gear chamber through the partition opening.