A flow control valve includes a resin housing body, a valve member, a retainer plate, a drive unit, and a protective wall. The resin housing body is substantially cylindrical. The valve member axially moves back and forth in the housing body to regulate a flow rate of a liquid. The retainer plate is fastened to the housing body at a position axially outward from the bearing to retain the bearing in the housing body. The drive unit drives the valve stem at a position outward from the bearing to move the valve member back and forth. The protective wall surrounds an outer circumferential surface of the housing body at a position radially outward from a portion of the housing body that receives the bearing to form an air layer portion between the protective wall and the outer circumferential surface of the housing body.