A drive device that includes a motor having a rotor disposed relative to a stator, a cover having a one-end-closed cylinder shape and positioned on one axial end side of the motor, and a substrate on the inside of the cover perpendicular to a motor shaft having electronic components implemented on the substrate. The drive device also includes a connector positioned on a motor side of the substrate with an opening that is connectable to an external terminal. The opening of the connector faces outward relative to the motor shaft. The drive device further includes a heat sink having a frame end part and a heat receiving part formed in one body. The drive device increases heat capacity of the heat sink without increasing its height.