Struck idiophones is one of the categories of idiophones (that is, any musical instrument that creates sound primarily by the instrument as a whole vibrating—without the use of strings or membranes) that are found in the Hornbostel-Sachs system of musical instrument classification.

Struck idiophones are categorised as 11 in the Hornbostel-Sachs system. There are two main categories of struck idiophones, directly (111) and indirectly (112) struck.

According to Sachs,

"Struck Idiophones consist of one or several pieces made of a sonorous substance and struck with a stick or a similar device with rotary motion of the arm. Again, they are distinguished by their materials."

Directly struck idiophones produce sound resulting from a direct action of the performer as opposed to the indirectly struck idiophones. The player strikes the instrument with a direct action, either by hand or by mechanical intermediate devices, beaters, keyboards, or by pulling ropes, etc. It is definitive that the player can apply clearly defined individual strokes and that the instrument itself is equipped for this kind of percussion.

There are two main categories of directly struck idiophones, concussion idiophones (111.1) and percussion idiophones (111.2).

Two or more complementary sonorous parts are struck against each other.

According to Sachs, idiophones struck together: