Divertimento (English: /dɨˌvɜrtɨˈmɛntoʊ/; from the Italian divertire — to amuse) is a musical genre, with most of its examples from the 18th century. The mood of the divertimento is most often lighthearted (as a result of being played at social functions) and it is generally composed for a small ensemble.

Divertimento is used to describe a wide variety of secular instrumental works for soloist or chamber ensemble. It is a kind of music entertainment although it could also be applied to serious genres. After 1780, the term generally designated works that were informal or light.

As a separate genre, it appears to have no specific form, although most of the divertimenti of the second half of the 18th century go either back to a dance suite approach (derived from the 'ballet' type of theatrical divertimento), or take the form of other chamber music genres of their century (as a continuation of the merely instrumental theatrical divertimento). There are many other terms which describe music similar to the divertimento, including serenade, cassation, notturno, Nachtmusik; after about 1780, the divertimento was the term most commonly applied to this light, "after-dinner" and often outdoor music. Divertimenti have from one to nine movements, and there is at least one example with thirteen. The earliest publication to use the name "divertimento" is by Carlo Grossi, in 1681, in Venice (Il divertimento de' grandi: musiche da camera, ò per servizio di tavola) --and the hint that the divertimento is to accompany "table service" applies to later ages as well, since this light music was often used to accompany banquets and other social events.