The control valve includes a valve body; a spool hole formed in the valve body; a spool slidably fitted in the spool hole; a pilot chamber into which a pilot fluid to actuate the spool is led; a discharge passage to discharge a hydraulic fluid to an outside of the valve body; a spiral groove to communicate with the discharge passage, the spiral groove being formed in a spiral shape on an outer periphery of the spool; and at least one axial groove to cause the pilot chamber and the spiral groove to communicate with each other, the axial groove being formed along an axial direction of the spool on an inner surface of the spool hole.