A rotary compressor comprises an input shaft, a compressor component and a clutch component movable between an engaged position where the compressor component is connected to the input shaft to allow a torque to be transmitted from the input shaft to the compressor component and a disengaged position where the compressor component is disconnected from the input shaft to prevent the torque from being transmitted from the input shaft to the compressor component. A hydraulic pump is drivingly connected to the input shaft to discharge a pressurized working fluid upon the rotation of the input shaft. The clutch component includes a clutch member disposed within a clutch cylinder and cooperating therewith to define a pressure chamber. A valve unit is movable between a position where the pressurized working fluid from the pump is allowed to be applied to the pressure chamber to cause the clutch member to be engaged with a rotor member of the compressor component thereby moving the clutch component to the engaged position and a position where the pressurized working fluid from the pump is prevented from being applied to the pressure chamber to prevent the clutch member from engaging with the rotor member to move the clutch component to the disengaged position.