Provided is a motor device that prevents an increase in size in the radial direction of a motor while providing redundancy in controlling driving of the motor. A motor device includes: a motor including a motor shaft; a first control board on which a first power circuit and a first control circuit are mounted in combination, and a second control board on which a second power circuit and a second control circuit are mounted in combination, as control boards constructing a circuit that controls driving of the motor; and a housing that accommodates the motor and the control boards together. Each of the control boards is disposed to cross a radial direction that is orthogonal to an axial direction of the motor.