The timpani (/ˈtɪmpəni/; Italian pronunciation: [ˈtimpani]) or kettledrums (also informally called timps) are musical instruments in the percussion family. A type of drum categorised as a hemispherical drum, they consist of a membrane called a head stretched over a large bowl traditionally made of copper. Thus timpani are an example of kettledrums, also known as vessel drums and semispherical drums, whose body is similar to a section of a sphere whose cut conforms the head. Most modern timpani are pedal timpani and can be tuned quickly and accurately to specific pitches by skilled players through the use of a movable foot-pedal. They are played by striking the head with a specialized beater called a timpani stick or timpani mallet. Timpani evolved from military drums to become a staple of the classical orchestra by the last third of the 18th century. Today, they are used in many types of ensembles, including concert bands, marching bands, orchestras, and even in some rock bands.

Timpani is an Italian plural, the singular of which is timpano, though the singular may also be referred to as a timpanum. In English the term timpano is only widely in use by practitioners: a single drum is often referred to as a timpani, leading many to incorrectly pluralize the word as timpanis. A musician who plays timpani is a timpanist.

First attested in English in the late 19th century, the Italian word timpani derives from the Latin tympanum (pl. tympana), which is the latinisation of the Greek word τύμπανον (tumpanon, pl. tumpana), 'a hand drum', which in turn derives from the verb τύπτω (tuptō), meaning 'to strike, to hit'. Alternative spellings with y in place of either or both i's—tympani, tympany, or timpany—are occasionally encountered in older English texts. Although the word timpani has been widely adopted in the English language, some English speakers choose to use the word kettledrums. The German word for timpani is Pauken; the Swedish word is pukor in plural (from the word puka), the French and Spanish is timbales, not to be confused with the latin percussion instrument, which would actually supersede the timpani in the traditional Cuban ensemble known as Charanga.

The tympanum is mentioned, along with a faux name origin, in the Etymologiae of St. Isidore of Seville:

Tympanum est pellis vel corium ligno ex una parte extentum. Est enim pars media symphoniae in similitudinem cribri. Tympanum autem dictum quod medium est, unde et margaritum medium tympanum dicitur; et ipsud ut symphonia ad virgulam percutitur.

The tympanum is a skin or hide stretched over one end of a wooden frame. It is half of a symphonia (i.e. another type of drum) and it looks like a sieve. The tympanum is so named because it is a half, whence also the half-pearl is called a tympanum. Like the symphonia, it is struck with a drumstick.

The reference comparing the tympanum to half a pearl is borrowed from Pliny the Elder.

The basic timpano consists of a drum head stretched across the opening of a bowl typically made of copper or, in less expensive models, fiberglass or aluminum. In the Sachs–Hornbostel classification, this makes timpani membranophones. The head is affixed to a hoop (also called a flesh hoop), which in turn is held onto the bowl by a counter hoop. The counter hoop is usually held in place with a number of tuning screws called tension rods placed regularly around the circumference. The head's tension can be adjusted by loosening or tightening the rods. Most timpani have six to eight tension rods.