To provide a device for reducing the underwater radiated noise of a propeller which is unnecessary for any installation work of complicated air supply pipes, and a propulsion device or a ship having the same.

The device for reducing the underwater radiated noise of the propeller which is unnecessary for any installation work of complicated air supply pipes, and the propulsion device or the ship having the same has a nozzle arranged around the propeller, an ultrasonic wave generator mounted on an inner surface of an inner wall of the nozzle, and a power supply device for generating ultrasonic waves to supply the drive transmission to the ultrasonic wave generator.