A percussion instrument is any object which produces a sound by being struck with an implement, shaken, rubbed, scraped or by any other action which sets the object into vibration with musical intent. All instruments such as drums and bells fall into this category.

Percussion instruments are often classified by the method used to produce the sound, including:

- idiophones - where the entire instrument is caused to vibrate (e.g. cymbal, marimba, wood block)

- membranophones - which have a skin or membrane which is caused to vibrate (hence all drums)

Percussion instruments may be further divided into those instruments that produce a definite pitch and those that do not. Some whistles (aerophones) are also included in this category of instruments because they tend to be considered sound effects rather than serious instruments.