A nozzle for a cleaner includes a nozzle main body, a rotation cleaning unit rotatably connected to the nozzle main body, the rotation cleaning unit including a rotation plate provided with a mop, and a water supply flow path configured to supply water from a water tank to the rotation cleaning unit, the water supply flow path having an outlet. The rotation plates includes a central shaft, at least one water passage hole spaced apart from the central shaft in a radial direction to receive water directly from the outlet of the water supply flow path, and a water blocking rib located outside of the water passage hole in the radial direction.