A control valve includes a casing that has a port in which an outflow opening is formed, a joint that is joined to an opening end surface of an outflow opening in the port, a rotor that is rotatably accommodated inside the casing, a slide ring that has a slide surface for sliding on an outer circumferential surface of the rotor, a sealing ring that is interposed between an inner circumferential surface of the port and an outer circumferential surface of the slide ring, and a holder that is disposed between the inner circumferential surface of the port and the outer circumferential surface of the slide ring and holds the sealing ring from an outer side in a port axial direction with respect to the sealing ring. The holder is disposed to be separated from at least any of the joint and the port.