To provide an oxygen water generator causing little noise, efficiently dissolving oxygen into drinking water, a water cleaner containing thereof, and a water drinking device or a water cooler.

The oxygen water generator includes a housing, a water storage tank set inside the housing, an oxygen generator set inside the housing, and a mixing portion mixing water fed from the water storage tank with oxygen formed by the oxygen generator. The mixing portion includes a hollow fiber membrane therein, the hollow fiber membrane includes a water inlet part with at least one side end of the hollow fiber fixed to the water inlet part and a protrusion part with a body of the hollow fiber protruded. Water and oxygen are made to flow into an opening of at least one side end fixed to the water inlet part, and discharged to the protrusion part.