A motor-driven compressor that includes a compression unit, an electric motor, a housing, a cover, and a motor driving circuit. A metal terminal electrically connects the electric motor to the motor driving circuit. A coupling base is coupled to the housing, and the motor driving circuit is coupled to the coupling base. Each of the coupling base and the housing includes an insertion portion through which the metal terminal is inserted. At least one of the coupling base and the housing includes a protrusion. The protrusion is separated from the insertion portions. At least the other of the coupling base and the housing includes a receiving portion that receives the protrusion. The coupling base is positioned relative to the housing by connection of the insertion portion of the coupling base and the insertion portion of the housing and by engagement of the protrusion and receiving portion.