A cyclone dust collector includes a cyclone body including a first cyclone chamber to centrifugally separate dust from drawn-in air for a first time, a plurality of second cyclone chambers to centrifugally separate dust from the drawn-in air for a second time, and a plurality of discharge ports to cause the drawn-in air to be discharged from the plurality of second cyclone chambers; an upper cover to cover an upper portion of the cyclone body, the upper cover having an inner wall facing the plurality of discharge ports; and a noise reduction part disposed between the plurality of discharge ports and the inner wall of the upper cover, to reduce noise generated inside the upper cover by the air discharged through the plurality of discharge ports. Therefore, it is possible to reduce noise generated inside the upper cover of the cyclone dust collector.