A drive device includes a control unit with a substrate. The control unit is disposed on an opposite side of a motor relative to an output shaft of the motor. The substrate has electronic components mounted on the substrate. A motor line connects the substrate and a winding. A frame member bears the surface-mount electronic components on a first surface of the substrate. A bearing holder holds a bearing that bears a shaft. A motor line takeout part allows the motor line to extend toward the control unit. A partition wall separates the shaft and the control unit at a radial inside position of the motor line takeout part. Such a structure prevents foreign matter from intruding into a control unit accommodating space.