A suction nozzle, and a vacuum cleaner, and a robot cleaner includes a housing having a suction port formed on a bottom surface thereof and a suction flow path formed on an inside thereof to communicate with the suction port, and a vibration cleaning unit arranged on the suction flow path to pass therethrough air including pollutants that flows in through the suction port, wherein the vibration cleaning unit includes a vibration source, a vibration transfer frame configured to accommodate the vibration source, and a vibration bar configured to receive vibration transferred from the vibration transfer frame to resonate.