An ultrasonic cleaner, sometimes called a sonicator, is a cleaning device that uses ultrasound (usually from 20–400 kHz) and an appropriate cleaning solvent (sometimes ordinary tap water) to clean delicate items. The ultrasound can be used with only water but solvent is advised; it enhances the effect of a solvent appropriate for the item to be cleaned and the soiling.

Ultrasonic cleaners are often used to clean jewellery, lenses and other optical parts, watches, dental and surgical instruments, fountain pens, industrial parts and electronic equipment. They are used in many jewellery workshops, watchmakers' establishments, and electronic repair workshops.